About the Mineral Black Onyx
Black onyx is a form of agate that is black with white strips or ribbons flowing through it. It is given as a gift for both the seventh and tenth wedding anniversaries. The name "black onyx" came from an ancient Greek legend: The goddess Venus was sleeping and Eros (Cupid) clipped her fingernails. The stones that were found in place of her fingernail clippings were named onyx, meaning "nail of a finger or claw." Does this Spark an idea?
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Uses
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Black onyx is a rare mineral used in jewelry as beads as well as cabochon-cut center stones for rings, earrings and necklaces. Cameos carved from black onyx are strongly desired by collectors due to the black and white stripes that give it an unusual appeal. For cameos, the black portion of the mineral is left in the background and the white portion is highlighted. Since black onyx is a good mineral for carving, it is also used for decorative purposes, and it is a favorite mineral of artists.
Imposter Industry
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Sardonyx is a form of agate that is red or brown with white strips. Sardonyx is often mistaken for black onyx due to its white stripes and similar composition. True black onyx is rare and valuable.
Some unscrupulous jewelers will dye other stones, such as chalcedony, black and try to sell them as black onyx.
Black onyx also has been confused with a form of calcite found and mined in cave systems in Mexico and Pakistan. This form of calcite is often carved into chess sets, decorative figures, book ends and talismans. Marketers sometimes call this form of calcite "Mexican onyx," or "onyx-marble."
Man-made materials have also popped up in the cameo market as counterfeiters try to sell black and white cameos under the onyx name.
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Mining Locations
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Black onyx is mined in Brazil, Canada, the Czech Republic, Germany, Madagascar, the United Kingdom, the United States and Uruguay.
Characteristics
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Black onyx, also known as onicolo, is formed in a trigonal system--it has three sides and grows in a crystal formation. Black onyx has a vitreous lustre that is as smooth to the touch as glass. Mohs scale of hardness rated black onyx at 6.5 to 7.0. Mohs scale of hardness rates the hardness of minerals on a scale from 1, for talc, to 10, for a diamond.
Jewelers may heat and dye black onyx in order to enhance the color. This common practice in the jewelery industry does not affect the value of the stone.
Care
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Black onyx should be cleaned with care. Use a soft cloth and very mild soap in order to clean black onyx. Do not use cleansers that are not made from natural ingredients, or brushes.
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References
- Photo Credit black pawns image by Ekaterina Lozanova from Fotolia.com
Comments
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it's a beautiful stone.
