Gems, Minerals, & Rocks

…and Wannabe Gems

Banded Agate and Seed Pearl Victorian Brooch.

Agate

Agate is a variety of chalcedony found in many different colors and degrees of translucency. There are several varieties of ...
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Alabaster

Alabaster

Alabaster Carving on Onyx Background. Alabaster is a name used for gypsum and calcite but has also been used to indicate selenite ...
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Alexandrite and Diamond Ring.

Alexandrite

Alexandrite is a variety of chrysoberyl with a distinct change of color when viewed in incandescent and fluorescent light. The ...
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Almandine Garnet Ring.

Almandine

These deep purplish-red garnets were often featured in Victorian Jewelry. When they are cut en cabochon they are referred to as "carbuncles." For more ...
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Wild Strawberry Brooch with Amazonite Leaves.

Amazonite

Amazonite, a variety of the microcline series of the feldspar group, gets its name from the Amazon River. A gridlike structure visible in ...
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Art Deco Amber Teardrop Earrings. Signed Day, Clark & Co.

Amber

In the forest primeval, a creature calls…Its echo is heard for millions of years.Frozen in time; the drama unfolds--A death ...
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Amethyst Brooch with Pearl Surround..

Amethyst

Amethyst is the most coveted member of the quartz family. It can be found in shades ranging from a very ...
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Ametrine Diamond and Opal Dragonfly Brooch. Photo Courtesy of Christie's.

Ametrine

Ametrine is a variety of quartz consisting of both amethyst and citrine with zones of both purple and yellow. Most ...
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Andalusite var. Chiastolite.

Andalusite

The name, Andalusite, is an homage to the city of Andalusia, Spain. Gem quality examples of this mineral species are ...
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Antique Demantoid Garnet Earrings.

Andradite

Andradite Garnet var. Demantoid ...
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Apatite

Apatite

Gems & Gemology: The Quarterly Journal of the Gemological Institute of AmericaApatiteSummer 1962, Cat’s-Eye Apatite, p. 315, 2pp.Summer 1963, Yellow Cat’s-Eye ...
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Aquamarine Ring.

Aquamarine

Aquamarine is the blue variety of the mineral beryl. Most natural aquamarine is a pale bluish green, which was the ...
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Aragonite.

Aragonite

Aragonite is a naturally occurring crystal form of calcium carbonate and is a precipitate from salt and freshwater conditions. One ...
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Aventurine

Aventurine

Aventurine Quartz Rough ...
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Azurite.

Azurite

Gems & Gemology: The Quarterly Journal of the Gemological Institute of America. Azurite: Fall 1960, Azurite and its Absorption Spectrum, p ...
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Azurmalachite Specimen. Photo: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0.

Azurmalachite

Sources Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 22-23. Schumann, Walter. Gemstones of the World, New ...
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Benitoite.

Benitoite

Gems & Gemology: The Quarterly Journal of the Gemological Institute of America. Benitoite: Summer 1953, Benitoite, by Ehrmann, p. 317, 1p ...
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Morganite

Beryl

Beryl is a beryllium aluminum silicate that occurs in every color of the rainbow but is colorless in pure form; ...
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Georgian Style Multi-Gemstone Necklace.

Birthstones

The tradition of birthstones, or birthday stones, is a Polish 18th-century popularization1 of accumulated superstition and tradition which were ...
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Biwa Pearl and Diamond Brooch.

Biwa Pearl

Biwa pearls are a cultured pearl produced in a freshwater mussel native to Lake Biwa, Japan. Considered to be a non-nucleated pearl, they are ...
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Tiffany & Co. Bloodstone Intaglio Signet Ring with a Coat of Arms Seal.

Bloodstone

Who on this world of ours his eyesIn Aries opens shall we be wiseIf always on his hand there liesA ...
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Scottish Kilt Pin with Cairngorm

Cairngorm

Cairngorm is the name given to a citrine quartz variety with an amber or brown color traditionally mined in the Cairngorm Mountains in ...
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Conch Pearl Ring.

Calcareous Concretion

Calcareous concretions are pearl-like growths produced in mollusks that lack nacre. While still composed of calcite and aragonite, the crystals are much coarser. Some ...
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Calcite

Calcite

Sources Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 41-43. Schumann, Walter. Gemstones of the World, New ...
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Pinctada Margaritifera Shell. Image Courtesy of parels-ael.nl

Calcium Carbonate

Calcium carbonate is a primary component of the shells of marine mollusks and pearls. The outer shells of mollusks are ...
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Carbon

Carbon

Carbon is a chemical element on the periodic table. Carbon is the 15th most abundant element in the earth's crust ...
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Victorian Garnet and Diamond Pendant.

Carbuncle

A large almandine garnet that is cut en cabochon. These deep purplish-red garnets were popular in Victorian jewelry. Victorian Garnet and Diamond Pendant ...
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Carnelian Intaglio Ring.

Carnelian

Carnelian (or cornelian) is the translucent red variety of chalcedony which in its turn is a form of cryptocrystalline quartz. It's been known and used since ...
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Giuliano Cave Pearl

Cave Pearls

Cave pearls are not actually pearls, they are a calcareous concretion occurring in subterranean limestone caves. While they bear a resemblance to pearls, ...
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Art Deco Chalcedony, Amethyst, Glass and Diamond Bracelet by Black Starr and Frost

Chalcedony

Chalcedony is cryptocrystalline quartz. It is semitransparent to opaque and, depending on its color, chalcedony is further divided into several varieties. HistoryAll ...
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Chlorastrolite.

Chlorastrolite

Chlorastrolite. Sources Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 49-50 ...
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Cat's Eye

Chrysoberyl

Chrysoberyl is among the most brilliant of gems and its hardness is only surpassed by diamonds and corundum. The name ...
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Tumbled Chrysocolla.

Chrysocolla

Chrysocolla is an intense blue-green to light blue variety of chalcedony. It can be translucent to semitransparent and is usually cut en cabochon. Tumbled ...
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Chrysoprase and Lapis Bypass Ring

Chrysoprase

Chrysoprase is the name reserved for bright green cryptocrystalline quartz. It is a subvariety of chalcedony and owes its beautiful green color to the ...
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French Japonesque Cinnabar, Diamond and Onyx Jabot Pin

Cinnabar

French Japonesque Cinnabar, Diamond and Onyx Jabot Pin.  Online Texts on Cinnabar Some Cinnabar Deposits in Western Nevada by Knopf ...
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Vintage Citrine Bracelet.

Citrine

Citrine is a yellow or golden variety of quartz, colored with iron. Natural citrine is relatively rare, occurring in Brazil, ...
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Multi-Gemstone Necklace.

Colored Stone

Colored stones are all gemstones that are not a diamond. The term is used as a general catch-all for gemstones.Georgian Style ...
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Belle Epoque Conch Pearl and Diamond Necklace.

Conch Pearls

A conch pearl is not technically a pearl at all, but a white or pink (sometimes brown or yellow), non-nacreous, product of ...
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Art Deco Black Mother-of-Pearl Cuff Links.

Conchiolin

 A dark organic substance secreted by some invertebrate animal life including coral polyps and pearl producing mollusks. Conchiolin is the ...
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Copal

Copal

Copal is a fossilized organic resin. This amorphous yellow to brownish material is often confused with amber, but amber is much ...
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Art Deco Diamond and Coral Drop Earrings.

Coral

Coral is one of a very few organic gemstones. It consists of a mass of skeletons of tiny marine invertebrates ...
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Multi-Color Sapphire and Diamond Ring.

Corundum

DefinitionThe mineralogical name for Al2O3, the corundum family encompasses the gem varieties sapphire and ruby. It crystallizes in the trigonal structure and is ...
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Antique Demantoid Garnet Earrings.

Demantoid

At the end of the reign of Nicholas I, Emperor of Russia, and the beginning of the reign of Tsar ...
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3.30 ct. Asscher-Cut Diamond Engagement Ring.

Diamond

Diamonds are valued for their incredible brilliance and hardness. Diamonds are chemically pure carbon, identical to the graphite used for ...
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Grossular Diopside.

Diopside

Grossular Diopside. Photo Courtesy of Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 ...
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Druse

Druse

A surface covered with small projecting crystals, usually lining the sides of a cavity ...
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French Straight Line Emerald Bracelet.

Emerald

Emerald is the green variety of the mineral beryl, owing its vibrant color to a trace amount of chromium and ...
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Gem Quality Crystal.

Emeralds from Habachtal, Austria

Emeralds from Habachtal / Austria in Jewelry and arts by Nikolaus B.G. Lackner  IntroductionPicture of Trapeze Cut Habachtal Emerald Placed on ...
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Notes:

  1. Kunz, pp. 307-337