Black Onyx Crystal Bracelet

Onyx is chalcedony - microcrystalline quartz, SiO₂, Mohs 7 - in its solid black form. True onyx is banded in straight parallel layers, black against white; the all-black stone worn as beads is the black layer alone, and it takes a deep, even polish.

The colour reads as a complete, matte-to-glassy black with no translucency at the bead scale - a stone defined by its evenness rather than by pattern. Hard-wearing at Mohs 7, the same durability as the rest of the quartz family.

Honest naming: most solid black onyx in the trade is chalcedony that has been dyed black, a stable practice dating to Roman times.

Asked often

Is black onyx dyed?
Most solid black onyx is colour-stabilised chalcedony - a stable practice the Romans already used. Some is naturally black.

What is the difference from agate?
Both are chalcedony. Agate is banded in curved layers; onyx is banded in straight parallel layers. The all-black bead is the black band of onyx, polished on its own.

Is it hard-wearing?
Yes - Mohs 7, the same as the quartz family. It takes a high polish and holds it. Keep the cord dry and it lasts well.

How do I care for it?
Wipe with a soft, slightly damp cloth and dry. Hard and stable; keep the cord dry and avoid hard knocks that can chip a polished edge.