gemstone

Black onyx-style gemstone ring

Likely chalcedony (microcrystalline quartz, SiO₂), possibly dyed black; identification from the photo is uncertain

AI-generated identification · may be incorrect

The cabochon is opaque, glossy black with a pale reflection; chalcedony has Mohs hardness 6.5–7 and a trigonal microcrystalline structure, with no visible cleavage. The ring setting appears to be metal, not geological material.

Identified September 26, 2026More gemstone →

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Physical properties

Formation & geological history

If chalcedony, it formed as silica-rich fluids filled cavities or fractures and deposited quartz over geological time; age and locality cannot be determined from the image.

Uses & applications

Used in jewelry and ornamental objects; chalcedony is also collected as a lapidary material.

Geological facts

Black onyx is a trade name commonly applied to uniformly black chalcedony, often enhanced by dyeing.

Field identification & locations

A polished, domed cabochon and waxy-to-glassy luster are consistent with chalcedony, but glass or another stone can look similar; gem testing is needed for confirmation.