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Rare or unusual gemstones, generally meant to include those gemstones which occur so infrequently in gem quality that they are scarcely known except to connoisseurs, include andalusite , axinite , cassiterite , clinohumite and red beryl. Gemstone pricing and value are governed by factors and characteristics on the quality of the stone. These characteristics include clarity, rarity, freedom of defects, beauty of the stone, as well as the demand for them.
There are different pricing influencers for both colored gemstones, and for diamonds. The pricing on colored stones is determined by market supply-and-demand, but diamonds are more intricate. Diamond value can change based on location, time, and on the evaluations of diamond vendors.
There are a number of laboratories which grade and provide reports on gemstones. Each laboratory has its own methodology to evaluate gemstones. A stone can be called "pink" by one lab while another lab calls it "padparadscha". One lab can conclude a stone is untreated, while another lab might conclude that it is heat-treated. Country of origin has sometimes been difficult to determine, due to the constant discovery of new source locations. Determining a "country of origin" is thus much more difficult than determining other aspects of a gem such as cut, clarity, etc. Gem dealers are aware of the differences between gem laboratories and will make use of the discrepancies to obtain the best possible certificate.
A few gemstones are used as gems in the crystal or other form in which they are found. Most however, are cut and polished for usage as jewelry. The picture to the left is of a rural, commercial cutting operation in Thailand. This small factory cuts thousands of carats of sapphire annually. The two main classifications are stones cut as smooth, dome shaped stones called cabochons , and stones which are cut with a faceting machine by polishing small flat windows called facets at regular intervals at exact angles.
Stones which are opaque or semi-opaque such as opal , turquoise , variscite , etc. These gems are designed to show the stone's color or surface properties as in opal and star sapphires. Grinding wheels and polishing agents are used to grind, shape and polish the smooth dome shape of the stones. Gems which are transparent are normally faceted, a method which shows the optical properties of the stone's interior to its best advantage by maximizing reflected light which is perceived by the viewer as sparkle. There are many commonly used shapes for faceted stones.
The facets must be cut at the proper angles, which varies depending on the optical properties of the gem. If the angles are too steep or too shallow, the light will pass through and not be reflected back toward the viewer. The faceting machine is used to hold the stone onto a flat lap for cutting and polishing the flat facets.
The color of any material is due to the nature of light itself. Daylight, often called white light, is actually all of the colors of the spectrum combined. When light strikes a material, most of the light is absorbed while a smaller amount of a particular frequency or wavelength is reflected. The part that is reflected reaches the eye as the perceived color. A ruby appears red because it absorbs all the other colors of white light, while reflecting the red. A material which is mostly the same can exhibit different colors. For example, ruby and sapphire have the same primary chemical composition both are corundum but exhibit different colors because of impurities.
Even the same named gemstone can occur in many different colors: This difference in color is based on the atomic structure of the stone. Although the different stones formally have the same chemical composition and structure, they are not exactly the same. Every now and then an atom is replaced by a completely different atom, sometimes as few as one in a million atoms. These so-called impurities are sufficient to absorb certain colors and leave the other colors unaffected. For example, beryl , which is colorless in its pure mineral form, becomes emerald with chromium impurities.
If manganese is added instead of chromium , beryl becomes pink morganite. With iron, it becomes aquamarine. Some gemstone treatments make use of the fact that these impurities can be "manipulated", thus changing the color of the gem. Gemstones are often treated to enhance the color or clarity of the stone.
Depending on the type and extent of treatment, they can affect the value of the stone. Some treatments are used widely because the resulting gem is stable, while others are not accepted most commonly because the gem color is unstable and may revert to the original tone. Heat can improve gemstone color or clarity.
The heating process has been well known to gem miners and cutters for centuries, and in many stone types heating is a common practice. Aquamarine is often heated to remove yellow tones, or to change green colors into the more desirable blue, or enhance its existing blue color to a purer blue. When jewelry containing diamonds is heated for repairs the diamond should be protected with boric acid ; otherwise the diamond which is pure carbon could be burned on the surface or even burned completely up. When jewelry containing sapphires or rubies is heated, those stones should not be coated with boracic acid which can etch the surface or any other substance.
They do not have to be protected from burning, like a diamond although the stones do need to be protected from heat stress fracture by immersing the part of the jewelry with stones in water when metal parts are heated. Virtually all blue topaz , both the lighter and the darker blue shades such as "London" blue, has been irradiated to change the color from white to blue. Most greened quartz Oro Verde is also irradiated to achieve the yellow-green color. Diamonds are irradiated to produce fancy-color diamonds which occur naturally, though rarely in gem quality.
Emeralds containing natural fissures are sometimes filled with wax or oil to disguise them. This wax or oil is also colored to make the emerald appear of better color as well as clarity. Turquoise is also commonly treated in a similar manner. Fracture filling has been in use with different gemstones such as diamonds, emeralds and sapphires. In "glass filled rubies" received publicity. Such treatments are fairly easy to detect. Synthetic gems are physically, optically and chemically identical to the natural stone, but are created in controlled conditions in a laboratory. Examples of simulated or imitation stones include cubic zirconia , composed of zirconium oxide and simulated moissanite , which are both diamond simulants.
The imitations copy the look and color of the real stone but possess neither their chemical nor physical characteristics. Moissanite actually has a higher refractive index than diamond and when presented beside an equivalently sized and cut diamond will have more "fire" than the diamond. Synthetic, cultured or lab-created gemstones are not imitations. For example, diamonds , rubies , sapphires and emeralds have been manufactured in labs to possess identical chemical and physical characteristics to the naturally occurring variety.
Synthetic lab created corundum , including ruby and sapphire, is very common and costs much less than the natural stones. Smaller synthetic diamonds have been manufactured in large quantities as industrial abrasives , although larger gem-quality synthetic diamonds are becoming available in multiple carats.
Whether a gemstone is a natural stone or lab-created synthetic , the physical characteristics are the same. Lab-created stones tend to have a more vivid color to them, as impurities are not present in a lab and do not modify the clarity or color of the stone, unless added intentionally for a specific purpose. From Wikipedia, the free encyclopedia. For other uses, see Gemstone disambiguation.
For the James Bond character, see Hurricane Gold. For other uses, see Gem disambiguation , Gems disambiguation , and Jewels disambiguation. This article or section may have been copied and pasted from another location, possibly in violation of Wikipedia's copyright policy. A popular idea is that the melted material then was flung into the air and cooled into glass as it landed over the area Stones can be an attractive yellow or brown color but are usually small.
Moonstone or "Adularia", an orthoclase feldspar, was originally named for an early mining site at Mt. From this tradition we derive the term "adularescence" which is the optical phenomenon of iridescence which creates a billowy, floating blue to white light in this gem. Adularescence is due to diffraction of light as it hits thin, alternating layers of orthocl Compact, fibrous material is cabbed because the fibers provide a chatoyancy that sometimes yields weak catseyes. Coloration in the material is due to staining. This is a relatively unexciting mineral, and gems are equally uninspiring. Nevertheless, it has been reported as being cut for collectors.
A member of the beryl family, morganite shows a range of pink colors due to traces of manganese. Recently, this gemstone has seen an increase in popularity and value. Like most beryls, morganite makes an excellent jewelry stone. The color of Namibian nambulite is a striking orange-red, very intense, and not really like any other gem I have seen. Cut stones would be both extremely rare and quite magnificent, perhaps bearing some similarities to rhodonite. All three minerals are fibrous or elongated zeolite minerals. Faceted gems are almost always elongated emerald cuts or step-cuts.
These inclusions produce a sheen that yields a catseye effect in cabochons. Nephrite is one of the two distinct minerals commonly known as jade. While nephrite doesn't match the variety or the fine green colors found in jadeite, it's even more durable as a gem material for jewelry and carved objects. An overview on Neptunite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Neptunite gems.
Gem cutters typically carve this gem material into cabochons for jewelry use. Obsidian is an attractive material and displays a wide variety of appearances. Snowflake obsidian, with spherulites of cristobalite, is widely used in jewelry as beads and cabochons. Some of these have been faceted. Green, blue, and reddish transparent Oligoclase gems are feldspars that are part of a solid state series between albite and anothrite. Opals are in a class by themselves. As a species, opal is so unique it has its own descriptive vocabulary. More than any other gem, each opal is distinctly individual.
Opals are also the most delicate gemstones commonly worn and require special care. The article points out that prior to the finds of substantial amounts of facetable crystals in Oregon, most sunstone, much of which came from the Orient, was used for cabbing material, or in the production of pale yellow, low value, faceted goods. Such is the case no more. Orthoclase is best known for moonstone.
It is occasionally a transparent, faceted gem. Note that moonstone is occasionally a labradorite. Until , only three painite crystals were known to exist. Since then, additional discoveries have produced many more specimens of this deep red gemstone, but facetable material remains very rare.
This unusual, parchment-like mineral can be cut into cabochons or carved. Cerulean blue papagoite crystals are too small for faceting. However, massive material mixed with quartz can be cabbed, while quartz crystals with papagoite inclusions make striking specimens for collectors. The amphibole group is very large and extremely complex and contains numerous distinct species that vary subtly in chemistry and physical properties. The identity of a specific amphibole is determined An overview on Parisite Jewelry and Gemstones.
Covers details and essential information on the physical properties and characteristics of Parisite gemstones. Pearls are the only gems found within living creatures, both salt and freshwater mollusks. However, most pearls on the market today are cultivated, since they now occur extremely rarely in nature. While they require special care, pearls have an enduring appeal for jewelry, particularly as the traditional June birthstone.
Fibrous pectolite has long been a curiosity for gem collectors. Compact material can make wonderful cabochons, and transparent crystals are rare and usually tiny. Larimar, blue pectolite from the Dominican Republic, has become a popular jewelry stone. Pentlandite resembles other yellowish metallic minerals and is cut by collectors as a curiosity.
The cut stones are quite attractive but too soft for hard wear. Periclase has been synthesized in large masses in the laboratory, but these have no market significance. A faceted natural periclase would be a great rarity due to the extreme scarcity of suitable faceting rough. The expected size would be less than 1 carat. Peridots have been prized as jewelry stones since ancient times.
Always green in color but with considerable variations, their particular shades depend on their locality of origin. Peristerite is primarily oligoclase with a complex mixture of feldspars. It has iridescence that is either blue or white. Perthite is a blend of microcline, albite and oligoclase. It is usually brown and white.
May have gold or white iridescence. Gem-quality, colorless, facetable petalite is rare and desirable to collectors. More so if the stones are large and free of inclusions. Rare phenakite is a very hard gem material suitable for jewelry. Usually colorless, cut stones have little fire but can be very bright. Rare phosgenite typically shows pale colors. This material is difficult to cut and too soft for jewelry wear. However, its strong yellowish fluorescence appeals to collectors of unusual gemstones. Unfortunately, this gem is quite fragile and difficult to cut, and few large facetable crystals exist.
Colorless pollucites lack fire when cut and are usually small. However, this very rare cesium mineral is a coveted collector's gem. An overview on Powellite Jewelry and Gems. Covers details and essential information on the physical properties and characteristics of Powellite gemstones. Prehnite is popular as a cabochon material among hobbyists because of its lovely green and blue-green to yellow colors. Completely transparent material is extremely rare but might be found in crystals from Asbestos, Quebec. Yellowish to greenish translucent material from Australia has been faceted and makes a striking cut gemstone with a rich color and interesting appearance, with a An overview on Prosopite Jewelry and Gemstones.
Covers details and essential information on the physical properties and characteristics of Prosopite gems. In reflected light, they have a dark gray, metallic luster. In transmitted light, the dark red of the garnet shows through. Proustite crystals have magnificent red colors and good brilliance. Although facetable, they're too soft for jewelry use but highly desired as collector's gems. The gem variety of pumpellyite, chlorastrolite, is best known from the Lake Superior district of the United States. It typically forms aggregates of packed fibers that are mixed with other minerals, resulting in a green and white pattern reminiscent of tortoise shell.
The effect is best observed when the fibers are in radial clusters that yield circular markings. This material is never transparent and is too soft for wear. However, cabochons are a magnificent purplish rose hues that have essentially no counterpart in the gem world. The material is available from Namibia in abundance and at low cost. Pyrargyrite is found in a number of localities in well-formed crystals, but these are usually small. However, larger, transparent crystals from Bolivia and Chile have provided a limited amount of cuttable rough.
Stones approaching 50 carats have been cut, but these tend to be too dark to be really attractive. They are exceedingly rare, however, since pyrargyrite is seldom transparen It has been used for centuries both in jewelry and as an ore of iron. The material is very brittle and heat sensitive and requires some care in cutting.
Cabochons are sometimes cut, but they have Pyrophyllite resembles talc in many ways and is indistinguishable by eye from soapstone. Chemical tests are needed to distinguish them. Pyroxmangite grains are rare, seldom clean enough to facet, and difficult to cut. However, when cut, they are extremely beautiful and rich in color.
An overview on Pyrrhotite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Pyrrhotite gems. An overview on Quartz Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of a Quartz mineral. Quartzite is a rock made up of tightly packed quartz grains. Sometimes, it contains small crystals that reflect light.
This material is called aventurine. Although this common arsenic sulfide mineral occurs worldwide, cut gem-quality realgar is extremely rare. This fine, red stone is very fragile, difficult to cut, and nearly impossible to wear. Originally known as bixbite, red beryl is one of the rarest, most desirable, and most expensive gemstones.
Most fine crystal specimens are zealously guarded by mineral collectors and are never faceted. Rhodizite is tough enough to make an excellent jewelry stone. However, it's quite a rare mineral. Faceted specimens are extremely rare and usually small and pale in color. Beautiful rose red to pink rhodochrosite crystals are popular with mineral collectors. Although very soft, opaque material has been fashioned into beads, cabochons, and carvings, while very rare translucent to transparent material has been cut into faceted gems.
Rhodolite is a garnet, intermediate in composition between almandine and pyrope. Its distinctiveness lies in its color, which is nearly always a purplish red. Ranging in color from pink to a fine rose red, rhodonite is a popular material for jewelry and decorative objects. Faceted rhodonite has an intense, beautiful color, but this material has a reputation as one of the most difficult gemstones to cut.
Rose quartz receives its coloring from titanium. It's always a light to medium pink, but sometimes picks up a violet shade. It's commonly carved into spheres or cabbed into a star stone. Rubellites are tourmalines with reasonably saturated dark pink to red colors and medium to dark tones. They make excellent jewelry stones, and ruby-red colored specimens without orange or brown overtones are highly prized. Ruby is red corundum, all other color varieties of corundum being referred to as sapphire.
That fact notwithstanding, the ruby color range includes pinkish, purplish, orangey, and brownish red depending on the chromium and iron content of the stone. The trace mineral content tends to vary with the geol Though perhaps best known as inclusions within other gems, rutile crystals themselves can be faceted or cabbed as curiosities for collectors. Synthetics can show a variety of colors and have even been used as diamond simulants. Pearls are one of our most ancient gems with records of commercial harvesting going back years.
Their natural occurrence is very rare, with only one in several million shellfish ever producing a pearl. Oysters are the best-known source, but clams, mussels, and abalone also produce pearls. Samarskite is a very heavy material from which lustrous black to brownish cabochons are sometimes cut as curiosities. The material is rather brittle and is not intended for wear.
It is rarely seen or displayed since black stones are not terribly attractive. Sometimes a stone is faceted in the nature of jet or marcasite. Sanidine is a mineral of volcanic rocks, rarely considered a gem. While occasionally brown or yellow, most examples are colorless. Few gems have held our attention over millennia as well as sapphire. The pure blue colors and excellent durability of this gem-quality member of the corundum family make for an exceptional gemstone.
However, not all sapphires are blue. They come in every color of the rainbow. Sapphirines are durable but very rare gemstones. Although named after their typically sapphire-blue color, these gems can occur in different hues and display pleochroism, too. Sarcolite is an extremely rare mineral. Although not well known, scapolite would make an attractive gem material for both jewelry enthusiasts and mineral collectors.
It comes in a wide variety of colors and can show dramatic fluorescence and phenomenal effects. With lovely colors and intense pleochroism, faceted scorodite is a prize for collectors of the rare and unusual. An overview on Sellaite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Sellaite gems. Senarmontite is a rare mineral, restricted in occurrence to the presence of antimony sulfide ores.
It is much too soft to wear, and the colors are usually nondescript. However, a faceted senarmontite in any size would be a great rarity. This essentially is another one locality mineral, where very small gems have been cut from an occasional crystal fragment that is not always even transparent. Shattuckite is often mixed with quartz, and data often reported for properties may be erroneous.
The cabochons are rich blue in color and very popular, but the material is not abundant and seldom seen on the market. Sea shells are one of our most ancient decorations. Our prehistoric ancestors used to string them into necklaces or hang them from cords as pendants. People still use them this way today. Shortite is an exceedingly rare, not overly attractive mineral. Cut gems are among the rarest of all faceted stones. The material is a carbonate and is therefore fragile and soft. Siderite is difficult to cut, but this light brown collector's gem has yielded faceted pieces of great beauty.
The fibrolite from Burma and Sri Lanka is well known to gem collectors, and highly prized because of its great scarcity. Blue and greenish gems are lovely, although very difficult to cut. Chatoyant material sometimes yields catseye fibrolites, which are also very rare. The material from Kenya is just as attractive as Burmese fibrolite but seems to be somewhat smaller in size. Simpsonite is an extremely rare gemstone.
The material from Western Australia is bright yellow-orange and very beautiful. The mineral is hard and durable, with no cleavage, and could easily become a popular gemstone if it were more abundant. Gems over 1 carat should be considered extremely rare because clean material is a very small percentage of the limited supply of simpsonite tha Long thought to be brown peridot, sinhalite was investigated in and found to be a new mineral.
When cut, it is richly colored, bright, and attractive, and resembles citrine, peridot, or zircon. Large gems are very rare, but smaller stones are available in the marketplace. Some people have reported that it was easier at times to find a large sinhalite for sale than a small one, Smaltite is a collectors oddity, cut only as cabochons. It is seldom seen in collections since it is not especially distinctive, with a color resembling other metallic sulfides and arsenides. Smithsonite occurs across the globe, but facetable crystals are extremely rare. These gems can show a wide range range of rich colors but are too soft for most jewelry use.
Smoky quartz comes in every shade of brown, from a light tan to nearly black. This gem is known for its large sizes. If you want a really big gem on a very small budget, this could be your stone. Tough, easy to cut or carve, and rich in color, typically blue, sodalite is highly desired by hobbyists. Even stones that lack transparency make lovely faceted gems. Sogdianite is an extremely rare mineral, suitable for cabochons.
The color is striking and the material is hard enough to take a good polish. It is usually mixed with other minerals, so the SG and hardness are variable. Chemical analysis may be required to differentiate sogdianite from sugilite, but the latter is far more abundant. Spessartite is somewhat rare. As with the other garnets, it always occurs in a blend with other species. Gems with the highest spessartite content are a light orange.
Those with an almandine content are reddish, to red brown in hue. Sphalerite occurs in many colors. With a dispersion over three times that of diamond and an adamantine luster, faceted specimens make beautiful additions to gem collections. However, they're too soft for most jewelry uses. Sphene, also known as titanite, has rich body colors, strong trichroism, and a fire that exceeds diamond. Although softer than many more popular gems, sphenes can make wonderful jewelry stones if set and maintained properly. Spinel is an important gem historically because it has been confused with other gemstones, especially ruby.
Extraordinarily difficult to cut, spodumene has several colorful varieties, such as hiddenite and kunzite, highly coveted for jewelry. This attractive but rather rare mineral has seldom been cut as a gemstone. Polished slabs and rough material appeared in at a mineral show in substantial quantities, however. This material is Mexican, translucent to opaque, and medium to dark purple in color.
Staurolite crystals in opaque cross shapes are popular gemstones. However, this material is very rarely transparent or facetable. These dark colored gems would make very durable jewelry pieces. Rare stibiotantalite possesses an interesting mix of physical and optical properties that help distinguish it from other earth-toned gemstones. Stichtite is not facetable, but the pink color is quite striking in cabochons.
Cut stones are especially beautiful when there are other minerals present to add splashes of green and yellow. This material somewhat resembles a pink, granular material from the USSR referred to as canasite. Stolzite is a rare mineral; much rarer than wulfenite and usually occurs in very minute crystals. However, the Australian crystals may be up to 1 inch Colors are usually pale and there is little fire; in addition, the high birefringence doubles back facets and kills the brilliance of the stone. Cut strontianites are, however, decidedly uncommon and worth pursuing for their scarcity value.
What is the color of sugilite? Grape jelly purple is a good description. The gemstone isn't very popular among consumers in North America. Most sugilite sales are in Asia. Nevertheless, this is a very rare and beautiful gem, if opaque and unusually colored. Although sulfur is very abundant, facetable material is not.
Sulfur is also enormously difficult to cut and almost impossible to wear, so faceted pieces have some scarcity value for collectors of unusual gems. Sunstones contain hematite or goethite inclusions, which reflect light in parallel orientation and create a sparkling sheen in gold to brown color shades. These gems may be oligoclase or labradorite in composition and are much admired as a cabochon material among hobbyists. Taaffeite reacts to most gemological tests like mauve-colored spinel, but can be distinguished on the basis of its birefringence. Additional stones will undoubtedly be discovered in the future generally misidentified as spinel as collectors search for these rarities.
Taaffeite is one of the rarest of mineral species, and surely among the very rarest and most desirable of all colle An overview on Talc Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Talc gemstones. Tantalite is too dark to be of use as a faceted gem but is sometimes cut as a collector curiosity, either faceted or in cabochons.
These could be of any desired size. Tanzanite has had a rapid rise to prominence among jewelers and gem enthusiasts. Although naturally reddish brown, this transparent zoisite variety achieves a stable, beautiful blue to violet color wth heat treatments. It has been argued that tektites originated as a result of violent explosive activity on the Moon and were thrown all the way to the Earth's surface. Other scientists, currently in the majority, argue that tektites are of terrestrial origin. The issue is being d Tephroite is generally reddish brown and barely translucent.
However, it takes a good polish and is massive enough to make good cabochons. Only the New Jersey and Australian localities seem to have provided such material, however. Faceted gems are unknown. For a long time, rare thaumasite crystals — pale, fragile, and with little to no fire — were interesting primarily as mineral specimens. Thomsonite cabochons take a high polish but are somewhat brittle. These are especially lovely when a pinkish gray eyelike pattern is present, but such material is rare, Lintonite, from Michigan, is translucent and green and is sometimes mistaken for jade.
A faceted thomsonite must be considered a great rarity. Crocidolite, blue asbestos, alters to quartz, but while retaining its fibrous structure. This material is frequently stained by iron, giving it a golden brown color. We know this material as tigers eye.
Unstained pieces, retaining their original blue color, are called Hawks Eye. There are also pieces with both colors. Topaz of any type is a good jewelry stone and it is historically one of the most important gemstones. With its relatively high refractive index and hardness of 8, with no special sensitivity to chemicals it can be used, with appropriate care, in any jewelry application. Although perfect cleavage does present a caution, this is mostly solved in the cutting stage --cutters generally o Tourmaline is one of our most popular gems.
No other mineral comes in more colors and some of the combinations are in a class by themselves. It is possible to misidentify tremolite, mistaking it for other amphiboles. Hexagonite is the rarest of the gem varieties of tremolite. Material containing more or less parallel fibers is somewhat chatoyant and yields weak catseyes. Triphylite is one of the world's rarest gems. The IGS had the extraordinary privilege of examining a discovery of facetable material from Brazil that showed previously unknown characteristics. An emerald-green colored variety of grossular garnet, tsavorite is one of the most popular and expensive varieties of garnet.
This gemstone can be faceted into many designs and can be used in rings, pendants, necklaces, and earrings. Gem collectors prize tugtupite for its rich colors and intense reaction to ultraviolet light. Sporadically used in jewelry, clean, faceted tugtupites are great rarities. This striking sky blue to blue-green gemstone has been prized by cultures all over the world for over 5, years.
Turquoise is favored by well-known modern jewelry designers as well as aficionados of American Southwestern and Native American jewelry. The fibrous material cuts interesting catseye cabochon gems, but they are curios only since they are much too soft and fragile for wear. The eye can be very strong, however. Sometimes ulexite occurs in seams, consisting of tightly packed parallel fibers. These are transparent along their length, and the packed aggregates act like an array of parallel glass fibers, displaying the pro Always a dark, rich green color, uvarovite is one of the rarest members of the garnet family.
Usually only seen as druzy on matrix, these crystals are seldom faceted. A faceted vanadinite may be considered a tremendous rarity. Fewer than ten such gems may have been cut. Arizona crystals tend to be very small, but the ones from Morocco reach a size of several inches. With beautiful green to blue-green colors and interesting patterns, variscite is a popular hobbyist material for cabochons.
Villiaumite is seldom discussed among collectors of rare gemstones because until recently no facetable material was known. The material from Los was reported in and has been cut into tiny gemstones of deep red color. Despite their small size, they are desirable because so few stones exist. The material from Quebec is larger but very scarce. Villiaumite is somewhat water-soluble Vivianite is so fragile and soft, any faceted gems would be difficult to handle safely, let alone wear.
Nevertheless, its blue and green colors are so rich, a few stones very few have been cut. Wardite is another of the many phosphates that have been cut by collectors. It is pale colored and not terribly attractive and is fairly soft and fragile. It is seen far more frequently as cabochons than as faceted stones. Wavellite is a very attractive mineral, well-known to collectors. Its radial aggregate crystal clusters can be cut into extremely interesting stones. An overview on Weloganite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Weloganite gems.
Whewellite is one of the most unusual minerals because of its chemical composition and occurrence. It is seldom seen by collectors, and even less thought of as a faceted gemstone. It is really just a curiosity, and there is nothing intriguing about it except its rarity. The dispersion is fairly high but hard to appreciate because of the usual small size of cut gems.
An overview on Wilkeite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Wilkeite gems. An overview on Willemite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Willemite gems. Easy to cut but too soft and fragile for jewelry, a faceted witherite would make an unusual addition to a gem collection. Wollastonite is strictly a curiosity and as a mineral is not especially rare. It resembles other white fibrous minerals, however, and is sometimes difficult to identify without using X—ray techniques Although aesthetically magnificent wulfenite crystals are often too thin, soft, and sensitive to cut for jewelry, rare faceted pieces are greatly prized by collectors.
The red of wulfenite, especially from the Red Cloud Mine in Arizona, is one of the richest colors in nature. Xonotlite is strong and can take a good polish. However, these gems are extremely rare, both as a species and cut specimens. Yugawaralite is a very rare colorless to pinkish zeolite mineral. Little facetable material exists, so a cut yugawaralite would be a prized addition to a gem collection. Small, cuttable crystals of very rare zektzerite are found only in a mountainous location in Washington state.
Faceted pieces would make prized specimens for any collection of American gems.
Zincite is a very rare mineral, essentially restricted to one important locality. Well, terminated crystals were found only up to about inches, but larger masses, weighing several pounds, have been encountered in the ore bodies. These are not especially interesting, but cabochons with red zincite, green willemite, and white calcite, peppered with black franklinite, are unique to Zircon is an underrated but magnificent gemstone.
When it is properly cut, it rivals diamond in beauty, but often the cutting is not correct and the gem is relatively dull and lifeless. The dispersion is very high, close to that of diamond. Zircon is very brittle and edges of stones are easily chipped and abraded. Zircon must be worn carefully to prevent damage.
The range of color i An overview on Zunyite Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of Zunyite gemstone. The International Gem Society IGS is the world's top resource for gem professionals, enthusiasts, and industry content. Brief title for your question. Please enter your question in detail here. After you submit your question, head to the forum to see it: Login Membership About Advertise Contact. Learn about stones — their color, price, and more. Browse through our list of precious, semi-precious, and lab-created stones and learn about their value for jewelry.
Actinolite View Profile Actinolite is a member of a series that contains varying amounts of iron and magnesium. Gem Profile Gem Value. Adamite View Profile Although adamite occurs in many localities, it's very rarely cut as a gem.
Agate View Profile Agate is a variety of chalcedony that exists in many colors and is often commercially dyed. Albite View Profile Albite, usually colorless but sometimes yellow, pink, gray or reddish. Algodonite View Profile Cabochons of these arsenides are bright, silvery, and metallic and are both attractive and unusual.
Almandine Garnet View Profile Almandine is perhaps the most common garnet species. Amazonite View Profile Amazonite is a variety of microcline, which is itself a variety of feldspar. Amber View Profile Amber is classed in various types: Amblygonite View Profile Amblygonite gems are usually pale straw yellow. Amethyst View Profile Amethyst is crystalline quartz in colors ranging from pale lilac to deep reddish purple. Ametrine View Profile Ametrine is a variety of quartz that displays bands of both amethyst purple and citrine yellow.
Analcime View Profile Large colorless crystals of Analcime are a great rarity although small transparent crystals are abundant. Anatase View Profile Anatase occurs in many beautiful colors, such as deep indigo and amber yellow. Andalusite View Profile Strongly pleochroic, andalusite can show shades of green, brown, and red when viewed from different directions.
Andesine View Profile These feldspars are rarely encountered in gem form. Anhydrite Angelite View Profile Rare and difficult to cut, anhydrite is seldom faceted. Anorthite View Profile Anorthite is the most calcic of the plagioclases, and sometimes makes up a distinctive rock known as anorthosite, which has been extensively studied. Apatite View Profile Although too brittle for most jewelry use, properly cut apatite gems are truly magnificent. Apophyllite View Profile Although not suitable for jewelry, apophyllite is a popular collector's piece.
Aquamarine View Profile Named after the color of sea water, aquamarine is the blue to blue-green member of the beryl family.
Aragonite View Profile Aragonite is more commonly found as a constituent of pearl and shell nacre than as a crystal suitable for gem cutting. Augelite View Profile Soft and brittle, rare augelites are difficult to cut and unsuitable for wear. Axinite View Profile When faceted, the members of the axinite mineral group are usually intensely trichroic, with considerable brilliance and rich brown and purple colors dominating. Azurite View Profile Faceted azurite is a great rarity, but even small stones are extremely dark, virtually black. Barite View Profile Massive white barite also called known as baryte looks like marble and could be used for decorative purposes.
Bayldonite View Profile Bayldonite is a nondescript greenish material that has been cut into cabochons by enterprising collectors of the unusual. Benitoite View Profile With dispersion higher than diamond and sapphire blue body color, benitoite is one of the most attractive of all rare gems. Beryl View Profile The beryls are among the most popular, and also the most expensive, of all gems.
Beryllonite View Profile Beryllonite is really not suited for wear, and since it is available only as small colorless stones, there is not much incentive to make jewelry out of it. Bismutotantalite View Profile Extremely rare as a cut gem, even in very complete collections. Black Onyx View Profile Onyx is banded chalcedony that is found in many different colors, including commonly black and white. Bloodstone View Profile Also known as heliotrope, bloodstone is the traditional March birthstone.
Boleite View Profile Cut boleite is strictly for collectors, since it is soft and very rare. Boracite View Profile With light blue and green colors, no cleavage, and high hardness, boracite is an uncommon mineral. Bornite View Profile Bornite is suitable only for cabochons. Brazilianite View Profile Brazilianite's lovely green to yellow colors make it a must for gem collectors. Breithauptite View Profile Breithauptite is a curiosity cut for collectors, although it could be worn with care in jewelry.
Brookite View Profile Brookite usually occurs in very dark colors, transparent only in small fragments. Brucite View Profile Brucites are extremely difficult to cut. Bustamite View Profile Bustamite is very similar in appearance and properties to rhodonite. Bytownite View Profile Bytownite is found in basic plutonic rocks, some metamorphic rocks, and meteorites.
Calcareous Concretions View Profile Several species of marine mollusks produce stony growths called calcareous concretions. Calcite View Profile Calcite is common and abundant throughout the world. Cancrinite View Profile Cancrinite is one of the most attractive of all opaque or translucent gem materials. Carnelian View Profile The best-known and generally least expensive variety of chalcedony is carnelian.
Cassiterite View Profile Cassiterite is a durable gemstone with tremendous dispersive fire, especially visible in properly cut pale-colored stones. Catapleiite View Profile The only reported cut catapleiite is from Mte. Celestite View Profile Soft, fragile, and hard to cut, celestite or celestine is seldom seen in collections. Ceruleite View Profile A little-known gem material of truly exquisite color, sky-blue ceruleite takes a very high polish easily and quickly. Cerussite View Profile Cut cerussite is as beautiful as diamond since has higher dispersion, is usually free of any body color, and has an adamantine luster.
Chabazite View Profile Although faceting chabazite isn't too difficult, it's too soft for jewelry. Chalcedony View Profile Technically, chalcedony kal SED' uh nee is any form of microcrystalline or cryptocrystalline quartz, meaning any form of quartz whose crystals are too small to be seen without high magnification. Chambersite View Profile Chambersite is an exceedingly rare mineral.
Charoite View Profile Named for the only locale in which it is found, the Charo River Valley in the former Soviet Union, Charoite is one of the few gems that is so distinctive in its color and patterns that a gemologist can feel justified in making a "sight" identification. Chicken-Blood Stone View Profile One of the most prized ornamental materials in China, chicken-blood stone has been used for centuries to create carvings with characteristic red markings.
Childrenite View Profile Cut childrenite is a great rarity, and all gems are small. Chiolite View Profile Chiolite makes a challenging gem. Chromite View Profile Chromite is shiny and black, and makes a curious-looking cabochon with no special attraction. Chrysocolla Chalcedony View Profile Marketed as "Gem Silica" this relatively rare, blue to blue-green, opaque to near transparent material is the most expensive type of chalcedony.
Chrysocolla View Profile Pure blue chrysocolla is extremely soft but interesting to gem collectors. Chrysoprase View Profile Chrysoprase is apple-green chalcedony that derives its color from nickel. Cinnabar View Profile Magnificent red cinnabar is extremely soft and fragile, so faceted material is rare. Citrine View Profile Citrine is the yellow to red-orange variety of crystalline quartz.
Clinochlore View Profile Clinochlore is a family of minerals in the chlorite group. Cobaltite View Profile Cabochons are interesting because of the lovely reddish metallic appearance of this mineral. Color Change Garnet View Profile Color change garnets are mostly pyrope and spessartite in composition. Color Change Sapphire View Profile Color change sapphires are those that change color between light sources.
Gem Profile Buying Guide. Cordierite View Profile The crystal structure of cordierite has many similarities to that of beryl; indialite, the dimorph, in fact has the same structure as beryl. Corundum View Profile Next to diamond, corundum is the hardest mineral known and is very compact and dense, with no cleavage. Covellite View Profile Although covellite has attractive blue colors and shows iridescence, this rare mineral is difficult to cut. Creedite View Profile Probably fewer than a dozen creedite gems have ever been faceted. Crocoite View Profile Lovely saffron-colored crocoite is quite a rare mineral.
Cryolite View Profile Cut cryolite is somewhat translucent, and has a "sleepy" look. Cuprite View Profile Cuprite is one of the rarest of all gems. Danburite View Profile A very durable gemstone, danburite is an excellent choice for jewelry use. Diamond View Profile Diamond is the most romanticized and heavily marketed of all gemstones. Diaspore View Profile Diaspore is hard enough to make a durable jewelry stone, but the typical light brownish color is not easy to sell. Dickinsonite View Profile This mineral is seldom even mentioned in the gem literature because it is so rare and has been so seldom cut.
Diopside View Profile Violane has been used for beads and inlay—transparent material is always very tiny. Dioptase View Profile Dioptase is abundant in mineral collections throughout the world and is not considered a great rarity, but faceted gems are extremely rare due to a paucity of clean fragments. Dumortierite View Profile Dumortierite is a beautiful and very hard material, eminently suitable for jewelry. Emerald View Profile Since the time of Cleopatra, emeralds have epitomized the color of green gemstones.
Enstatite View Profile Most gem enstatites have indices in the range 1. Eosphorite View Profile Faceted eosphorites in pale colors are quite attractive and easy to cut. Epidote View Profile The epidote mineral supergroup contains many related species of interest to collectors. Ettringite View Profile Ettringite is not generally facetable; any cut stone would be considered an extreme rarity.
Euclase View Profile Euclase is a hard enough gem to be worn safely in jewelry. Eudialyte View Profile Although cabochons could be cut from massive eudialite or translucent crystals, transparent material suitable for faceting is elusive and always small. Euxenite View Profile Euxenite is seldom seen in collections.
Feldspar View Profile Feldspars are the most common minerals at the Earth's surface. Fergusonite View Profile This mineral is not abundant and is known from various localities. Fluorite View Profile Although too fragile for most jewelry use, fluorites are often faceted for collectors. Fossilized Organisms View Profile Most people who have an interest in gemstones or nature have seen petrified wood, but fewer are aware of the many other types of fossilized organisms that can be fashioned into beautiful gems.
Freshwater Pearls View Profile Pearls are unique among gemstones, being the only ones found within a living creature and the only ones that requires no fashioning, cutting or polishing, before use. Friedelite View Profile Friedelite is not abundant, and gem-quality material is rarely seen even in large collections.
Gadolinite View Profile This is not a terribly attractive gemstone, but faceted gems would be a tremendous rarity. Gahnospinel View Profile Gahnospinel is a solid-state solution between spinel and gahnite. Gaylussite View Profile This mineral is very hard to cut because of extreme softness and cleavage.
Glass View Profile Glass has been used in jewelry for thousands of years. Grandidierite View Profile A rather rare mineral, lovely blue-green grandidierite is seldom seen in gem or jewelry collections. Grossular Garnet View Profile Grossular garnets come in almost every color, even colorless, except blue. Gypsum View Profile Gypsum is one of the most abundant minerals and is found especially in evaporite environments. Hambergite View Profile Although hard enough for jewelry use, rare hambergite is a gem for collectors of the unusual.
Hematite View Profile Hematite has a long history of use as a pigment. Hemimorphite View Profile Massive hemimorphite can have a very delicate, blue color. Herderite View Profile Herderite is a rare collector's gem, especially in larger sizes.
A gemstone is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis. Articles about gemstones written by a GIA Graduate Gemologist. Each article includes photos and information about the gem's phyiscal properties and geologic.
Hodgkinsonite View Profile Hodgkinsonite is one of the rarest of all collector gems. Holtite View Profile This mineral was first noted in but was not described in detail until Howlite View Profile Howlite is always opaque in nodules; it is an abundant material and easy to acquire.
Huebnerite View Profile It should not be difficult to find numerous small faceted huebnerites among larger gemstone collections. Humite View Profile Faceted chondrodite is almost unknown, a pity since the color is very rich and the material is hard and durable enough for wear. Hureaulite View Profile Hureaulite can show rich and lively pink, rose, and orange colors. Hurlbutite View Profile Hurlbutite is an extremely rare mineral. Hydrogrossular View Profile Hydrogrossular differs from the other garnets in that it is never transparent. Hyperitdiabas View Profile Hyperitdiabas is one of the most outstanding minerals I have encountered in recent years.
Inderite View Profile Inderite is very soft and difficult to cut, and only a few stones have been cut by hobbyists. Iolite View Profile This stone, which represents one of the few relatively available and affordable blue stone options, is rapidly gaining in popularity. Jadeite View Profile One of two distinct minerals commonly known as jade, jadeite is the rarer and harder variety.
Jasper View Profile Jasper is an opaque, solid or patterned variety of cryptocrystalline quartz. Jeremejevite View Profile Until the Namibian material was found, jeremejevite was an exceedingly rare mineral available only in microscopic grains. Jet View Profile Historically a popular black gem, jet has declined in popularity in modern times. Kurnakovite View Profile Kurnakovite is similar to inderite.
Kyanite View Profile Kyanite is very rare as a faceted gem, especially if free from inclusions and flaws. Langbeinite View Profile This material is nondescript and is cut solely as a curiosity. Lapis Lazuli View Profile The gem known as lapis lazuli, or simply lapis, is actually a rock, composed of lazurite, hauyne. Laserblue View Profile Laserblue is a rare, synthetic glass.
It's hard for glass but easy to chip. Lawsonite View Profile Lawsonite is extremely rare as a faceted stone, seldom reported and generally unavailable. Lazulite View Profile Lazulite makes a magnificent, deep blue gemstone. Lepidolite View Profile Reddish granular or massive lepidolite is usually slabbed for ornamental purposes, such as ashtrays paperweights, and bookends. Leucite View Profile Leucite is abundant in various lava rocks but is extremely rare in facetable crystals.
Linarite View Profile The blue color of linarite is magnificent, and it is a pity that large facetable rough has not been found. Ludlamite View Profile Ludlamite has a lovely green color but is too soft for wear. Magnesite View Profile Gems of completely transparent magnesite are both rare and beautiful. Malachite View Profile Malachite is one of the most popular and beautiful of decorative stones.
Mali Garnet View Profile Mali Garnet, one of the rarer varieties within the garnet group, is a mixture of the species grossular and andradite, therefore it is sometimes called "grandite. Mandarin Garnet View Profile While the colors of spessartite garnet gemstones cover a wide range of orange shades, the mandarin garnet is as pure orange as this variety can be.
Marcasite View Profile Marcasite has a long history of use as a decorative and jewelry material. Meliphanite View Profile Meliphanite is an extremely rare gemstone, and perhaps fewer than faceted stones have ever been cut. Mellite View Profile Mellite is a rare and unusual organic gemstone. Microcline View Profile Microcline is a variety of feldspar.
Microlite View Profile Ranging in color from pale yellow to brown, reddish, and green, microlite cabochons are prized by collectors. Milarite View Profile Milarite was originally known as a green mineral, until fine yellow crystals were discovered in Mexico in Millerite View Profile Millerite has a rich, attractive yellow color.
Mimetite View Profile Faceted mimetite is one of the rarest of all gems since only one pocket of transparent crystals has ever been found at Tsumeb , and few of these crystals have been cut. Moldavite View Profile Moldavite is a transparent to translucent olive to bottle green tektite, first found in at the Moldau River in Czechoslovakia.
Moonstone View Profile Moonstone or "Adularia", an orthoclase feldspar, was originally named for an early mining site at Mt. Mordenite View Profile Compact, fibrous material is cabbed because the fibers provide a chatoyancy that sometimes yields weak catseyes. Morganite View Profile A member of the beryl family, morganite shows a range of pink colors due to traces of manganese. Nambulite View Profile The color of Namibian nambulite is a striking orange-red, very intense, and not really like any other gem I have seen. Natrolite, Mesolite, Scolecite View Profile All three minerals are fibrous or elongated zeolite minerals.
Natural Glass View Profile Glass comes in several natural forms. All are used in jewelry. Nephrite Jade View Profile Nephrite is one of the two distinct minerals commonly known as jade. Obsidian View Profile Obsidian is an attractive material and displays a wide variety of appearances.
Oligoclase View Profile Oligoclase gems are feldspars that are part of a solid state series between albite and anothrite. Opal View Profile Opals are in a class by themselves. Orthoclase View Profile Orthoclase is best known for moonstone. Padparadscha Sapphire View Profile Padparadscha is a light to medium toned pink-orange to orange-pink hue sapphire. Painite View Profile Until , only three painite crystals were known to exist. Papagoite View Profile Cerulean blue papagoite crystals are too small for faceting.
Pargasite View Profile The amphibole group is very large and extremely complex and contains numerous distinct species that vary subtly in chemistry and physical properties. Pearl View Profile Pearls are the only gems found within living creatures, both salt and freshwater mollusks. Pectolite Larimar View Profile Fibrous pectolite has long been a curiosity for gem collectors. Pentlandite View Profile Pentlandite resembles other yellowish metallic minerals and is cut by collectors as a curiosity.
Periclase View Profile Periclase has been synthesized in large masses in the laboratory, but these have no market significance. Peridot View Profile Peridots have been prized as jewelry stones since ancient times. Peristerite View Profile Peristerite is primarily oligoclase with a complex mixture of feldspars.