17.40 ct ONYX – MEXICO

Onyx

I was fascinated as a child when I read about South American cultures of the past—the gruesome accounts of prisoners having their hearts cut out using super-sharp black blades made of onyx. While those ancient obsidian and onyx tools were forged for ritual and survival, we have taken a different path with our material. We didn’t make blades out of our onyx; instead, we have expertly faceted them into gemstones for you. There is something deeply powerful about a stone that carries such a heavy historical weight, transformed from a weapon of antiquity into a sophisticated, velvet-black gem that holds the light on its polished surfaces rather than cutting through it.

The Heritage & Discovery

Historical Significance: Onyx has been one of the most important ornamental stones throughout human history. From the cylinder seals of Mesopotamia to the amulets of Ancient Egypt, it has been prized for its ability to be carved into intricate detail. In many cultures, black onyx was seen as a stone of protection and grounded strength. Its use in ancient Mesoamerica for ceremonial blades—often confused with obsidian—highlights its capacity to hold an incredibly sharp edge due to its cryptocrystalline structure. It represents the intersection of art, ritual, and the raw utility of stone-age technology.

Discovery: The name is derived from the Greek word onux, meaning “fingernail” or “claw.” According to legend, Cupid cut the divine fingernails of Venus with an arrow while she slept, and the parings fell into the Indus River, turning into onyx. While it has been known since the dawn of civilization, its systematic classification as a parallel-banded variety of chalcedony distinguishes it from the curved banding of agate.

Important Mines: While onyx is found globally, some of the most historic and high-quality black and banded material comes from Brazil and Uruguay. Other notable deposits are found in India and Madagascar. We source our material from locations that provide the most solid, uniform black saturation, ensuring that when the stone is faceted, it produces a deep, mirror-like finish without the interference of unwanted white banding.

Mineralogical Profile

Description: Onyx is a cryptocrystalline variety of quartz, specifically a member of the chalcedony family. It sits at a 6.5 to 7 on the Mohs scale, making it very durable and excellent for daily wear. Unlike agate, which has curved bands, onyx is characterized by its parallel bands of color. While “Black Onyx” is the most famous variety, it is often found with alternating layers of black and white (often called sardonyx when reddish-brown is present). Its luster is vitreous to silky, and its dense structure allows it to take a polish so high it almost looks liquid.

Chemical Formula: SiO₂