Chemical Composition and Formation Process

Black Onyx is a variety of chalcedony, a form of microcrystalline quartz (SiO₂). It forms in volcanic rocks, where lava flows through silica deposition at low temperatures. The mineral’s deep black color is due to the presence of iron and carbon inclusions.

Names and Alternative Names

The name is derived from the Greek word “onyx,” meaning “claw” or “fingernail,” due to the stone’s resemblance to a polished fingernail. Alternative names include “Black Chalcedony,” highlighting its microcrystalline structure.

Mythology and Legends

In ancient Rome, the Black Onyx was believed to confer courage and protection in battle. It was often carved into seals and amulets. In Roman mythology, it is said to have originated from the goddess Venus. According to legend, Cupid cut her fingernails while she was sleeping, and the clippings turned into onyx stone.
In Indian mythology, onyx was used to ward off the “evil eye” and protect against negative energies. The Egyptians utilized it for its protective qualities, crafting it into jewelry and talismans.

Electric Cosmology

Mining, Production and Use

The mineral is mined worldwide, with significant deposits found in India, Brazil, and the United States. Historically, it has been used in carving and inlay work. Today, it is cut and polished into beads, cabochons, and various ornamental objects, popular in jewelry and decorative arts.