igneous

Labradorite

Labradorite (Ca, Na)(Al, Si)4O8

Hardness: 6-6.5 on Mohs scale; Color: Gray-green to dark gray, exhibiting an iridescent play of colors (labradorescence) in blue, green, and gold; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions.

Hardness: 6-6
Luster: Vitreous to pearly

Identified March 25, 2026More igneous →

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Physical properties

Formation & geological history

Formed in mafic igneous rocks like basalt and gabbro through the crystallization of magma; it is a member of the plagioclase feldspar series. Most commercial specimens are from the Proterozoic era (approximately 1.3 billion years ago).

Uses & applications

Primarily used as a semi-precious gemstone in jewelry, decorative carvings (like the heart shape shown), and high-end architectural surfaces like kitchen countertops.

Geological facts

Labradorite is famous for 'labradorescence,' an optical effect caused by internal lamellar twinning that diffracts light. Inuit legends claim the northern lights were trapped inside the rocks along the coast of Labrador.

Field identification & locations

Identify by rotating under a light source to reveal 'flashes' of hidden color; it typically looks like a dull gray stone until the light hits it at the correct angle. Common locations include Canada (Labrador), Madagascar, Russia, and Finland (Spectrolite).

Other igneous specimens

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Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous