Black Onyx

Chalcedony

6.5–7Hardness (Mohs)

SiO₂Chemistry

1Known origins & mines

Flat-banded black chalcedony beloved in Art Deco and men's signets. Natural black is rare — most is dyed Brazilian or Indian agate; Yemeni suleimani onyx carries Islamic talismanic tradition.

Known origins & mines

Khambhat Onyx Workshops · India

Active mining · Legendary locality

Cambay has processed carnelian and onyx for 4000 years — Indus Valley beads traveled Mesopotamian trade routes; heat treatment mastery persi…

Mineral family: Chalcedony

Chrysoprase Agate Jasper Blue Chalcedony Carnelian Bloodstone (Heliotrope)