mineral

Moonstone with Black Tourmaline

Orthoclase (KAlSi3O8) with Schorl inclusions

Hardness: 6.0-6.5 (Mohs scale), Color: Opalescent white/colorless with black inclusions, Luster: Vitreous to pearly, Crystal Structure: Monoclinic, Cleavage: Perfect in two directions

Hardness: 6

Identified April 18, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.0-6.5 (Mohs scale), Color: Opalescent white/colorless with black inclusions, Luster: Vitreous to pearly, Crystal Structure: Monoclinic, Cleavage: Perfect in two directions

Formation & geological history

Formed in plutonic igneous rocks (magmatic) and pegmatites. The moonstone effect (adularescence) is caused by the intergrowth of two types of feldspar that separate as the magma cools.

Uses & applications

Predominantly used in jewelry (cabochons), ornamental carvings, and by mineral collectors. It is also a popular stone in metaphysical circles.

Geological facts

The shimmering effect, known as adularescence, is caused by light scattering between microscopic layers of orthoclase and albite. The black spots are inclusions of Schorl, the most common type of Tourmaline.

Field identification & locations

Identify in the field by its distinct pearly sheen and the presence of needle-like or blocky black inclusions. Commonly found in Sri Lanka, India, and Madagascar.

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