mineral

Labradorite in Matrix

(Ca, Na)(Al, Si)4O8 (Plagioclase Feldspar)

Hardness: 6.0-6.5 Mohs. Color: Gray-green to dark gray matrix with signature labradorescence (blue/green/gold sheen). Luster: Vitreous to pearly. Crystal structure: Triclinic. Cleavage: Perfect in two directions.

Hardness: 6
Luster: Vitreous to pearly

Identified May 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms in mafic igneous rocks such as basalt or gabbro, and specifically in anorthosites. It crystallizes from cooling magma and develops its characteristic iridescent lamellae through a process called subsolidus exsolution.

Uses & applications

Polished into gemstones for jewelry, carved into decorative objects, and used in high-end countertops or architecture. Large, rough specimens are popular for geological collections.

Geological facts

The optical effect 'labradorescence' is caused by light reflecting off microscopic layers of different feldspar compositions within the stone. Inuit legends state the northern lights were trapped within rocks until a warrior freed them with a spear.

Field identification & locations

Identify by rotating in the light to find the 'flash' of color (schiller effect) and checking for two planes of cleavage. Found commonly in Labrador (Canada), Madagascar, Finland (Spectrolite), and Russia.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

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

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic

Green Apatite on Albite

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

mineral