History of Onyx Gemstones
The onyx is the birthstone for those who were born under the Western zodiac sign, Leo, and the Oriental sign of the zodiac, Ox. It can be many different numbers of colors, but astrologically speaking, the ones with reddish - brown shades are the most preferred. It is believed that Onyx exiles one’s grief away and brings fortune to those who brings the stone and serves as its possessor, which brings more confidence of personal strengths and enhances revival, visceral, sensitivity, and perception. It was also believed to help change, delete, and disregard bad habits.
Physical Properties of Onyx Gemstones
Onyx is a fine–grained type of the mineral compound chalcedony, which is prized as a gemstone. Onyx gemstone are also made up of compositions of submicroscopic crystals or aphanitic types of the quartz. It has an interchanging parallel and regular layer of unusual and different shades of colors which particularly includes the color white, brown, and black. Cameo brooches are made from onyx gemstone because of the layer of white color which is contracted well with a darker-shaded background.
Onyx’s are composed of a mineral compitsite of silicon dioxide. It has a hardness of 7 in Mohs scale and a specific gravity between 2.5 and 2.8. The gemstone also has a positive optic sign and a uniaxial optical character.
The most common color of onyx is pure black. Gem quality onyx is usually cut into beads, or as a cabochon. Sardonyx is a fine variant of onyx, which contains colored bands known as sard, which are shades of red, rather than black.
Onyx gemstones are found widely in Mexico, Pakistan, Northern India.