Black onyx is chalcedony — quartz in its smooth, microcrystalline form — in a black deep enough that most of what is sold has been helped there by an ancient dye process the Romans were already using. That is trade convention, two thousand years old, not a modern trick.
What black onyx is used for
It is the composure stone: self-command, steadiness under pressure, strength held rather than shown. Where black tourmaline guards the door, onyx steadies the hand. Victorian mourning jewellery leaned on it for exactly that quality. Root chakra, and the traditional stone of the self-possessed.
Worn dark and plain — a bead bracelet or signet does the work. This is the stone for the person who wants grounding without anything that looks mystical.
How to care for it
Cleanse with smoke or sound; water-safe briefly. Cleanse with smoke or sound; brief contact with water is fine.
Black Onyx in the shop
Stones that keep it company
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