mineral

Mother of Pearl and Onyx

Aragonite (Mother of Pearl) and Chalcedony (Onyx)

Hardness: 3.5-4 (MOP), 6.5-7 (Onyx); Color: Iridescent white/nacreous and black; Luster: Pearly and Vitreous; Structure: Orthorhombic (Aragonite), Trigonal (Quartz/Chalcedony)

Hardness: 3
Color: Iridescent white/nacreous and black
Luster: Pearly and Vitreous

Identified April 25, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3.5-4 (MOP), 6.5-7 (Onyx); Color: Iridescent white/nacreous and black; Luster: Pearly and Vitreous; Structure: Orthorhombic (Aragonite), Trigonal (Quartz/Chalcedony)

Formation & geological history

Mother of Pearl is organic-geological, formed as a lining in mollusk shells. Onyx is a cryptocrystalline form of quartz formed in gas cavities in volcanic rocks (lava).

Uses & applications

Primary use is in fine and decorative jewelry, inlay work, buttons, and watch faces.

Geological facts

Mother of Pearl (nacre) and Onyx have been used together in Zuni and Navajo inlay jewelry for over a century; Onyx was historically believed to provide protection and strength.

Field identification & locations

Identify by the signature iridescence/pearly play of color in the white sections and the high-polish, opaque deep black of the onyx. These materials are often used in 'mosaic' or 'channel' inlay techniques.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral