Green onyx is a type of quartz crystal with a very fine crystalline structure. It is one of the many gemstones used to make jewelry.

Green onyx has the chemical formula SiO2, which means that for every silicon atom there are two oxygen atoms attached. The chemical name is called silicon dioxide.

Green onyx has a color range from a very light lime-green color to a very light forest-green color. The green portion is marbled with a dark red-orange version, as onyx is found in a variety of different colors.

Green onyx is a hard stone, due to his compact crystalline structure. On the hardness scale, which ranges from 0 to 10, onyx falls between 6.5 and 7; compared with diamonds which are 10 and graphite (pencil leads) which are between 1 and 2.
   
Green onyx, according to traditional Spiritualism, fosters achievement. In Greek mythology, Eros clipped Aphrodite's fingernails while she slept, littering them across a beach, forcing The Fates to turn them to stone, producing onyx.