Hardness: 7.00
Refractive Index: 1.53-1.54
Specific Gravity: 2.60
Birthstone: February & July.
Astral Stone: Cancer, Leo, Capricorn
Anniversary Stone: 7th
Origination: Worldwide. South America is currently its’ most important source.
Care & Cleaning: To clean, rub lightly with a soft polishing cloth. An optional dab of olive oil will produce a beautiful shine. If necessary, a plain water rinse may also be used. Do not soak.
Fiction, Facts & Folklore:
Onyx is a close relative of the chalcedony mineral group.
Onyx is commonly seen as a black and white banded gem, although it can sometimes be found in a solid black state.
The gem that you know as “black onyx” is actually a form of agate which is treated to turn black. After soaking the agate for a period of about 30 days in a dense solution of sugar or honey, it is exposed to a sulfuric acid bath. This process has been used for centuries, and considered permanent under normal conditions.
Other colors of “onyx” seen at retail are often various shades of agate as well.
A brown and white banded mineral sometimes known as “Mexican onyx” is not actually onyx at all, but rather a mineral known as calcite.
If the bands of onyx are symmetrical, it is sometimes carved into cameos.
A dream of onyx once predicted the arrival of a happy marriage.
Onyx was believed by some to be the key to eternal life.