Onyx is a silicate mineral that is highly valued for its stunning banded appearance. The mineral’s name comes from the Greek word “onyx,” which means “claw” or “fingernail.” The unique parallel banding can be found in a range of colors, from black to nearly every other color.
The mineral is most commonly found in regions around the world including Greece, Yemen, Uruguay, Argentina, Australia, Brazil, Canada, China, Czech Republic, Germany, Pakistan, India, Indonesia, Madagascar, Latin America, the UK, and the United States.
Varieties
Onyx is a cryptocrystalline mineral made up of fine intergrowths of the silica minerals quartz and moganite. The mineral is part of the chalcedony family and has a unique parallel banding that sets it apart from other minerals. The most well-known varieties include sardonyx, which has red bands instead of black bands, and black onyx, which is one of the most sought-after types due to its deep black color.
Artificial treatments have been used for thousands of years to produce both black onyx and other colors like red and yellow. Sugar solutions have been used to soak or boil chalcedony, which is then treated with sulfuric or hydrochloric acid to carbonize the sugars that have been absorbed into the stone’s top layers. Dyeing treatments and heat treatment with nitric acid have also been used to lighten or eliminate undesirable colors.
Uses
It is a versatile mineral with a wide range of uses. It has been used for making jewelry, decorative objects, vases, bowls, and wall tiles. Due to its unique banding, onyx is often used for carving and engraving. Its bands make it perfect for creating designs and images, and it has been used for creating wall tiles and countertops. The mineral has been valued for centuries for its beauty and practical uses.
Historical Significance
Onyx has been used for thousands of years, dating back to ancient Egypt. The mineral was used to make bowls and other pottery items. It was also used in Minoan Crete, and the ancient Greeks and Romans knew about it. Pliny the Elder, a first-century naturalist, described both types of onyx and various artificial treatment techniques in his Naturalis Historia.
It has been associated with various superstitions over the years. The ancient Romans carried amulets of sardonyx engraved with Mars, the god of war, to give them courage in battle. Wearing sardonyx in Renaissance Europe was believed to bestow eloquence, and traditional Persian beliefs held that it helped with epilepsy. English midwives even used sardonyx to ease childbirth by laying it between the breasts of the mother.
Onyx has properties that resemble those of jasper, beside which it increases saliva in boys, and is said to produce terrible shapes in dreams. When applied to the eye it acts as if it were alive, by creeping about and removing anything noxious. A.G.H.
Source:Â 81, 307.