mineral

Sunstone

Feldspar (Oligoclase)

Hardness: 6 to 6.5 on the Mohs scale. Color: Orange, yellow, red, brown, with a characteristic metallic glitter or schiller caused by tiny copper or hematite inclusions. Luster: Vitreous to pearly. Crystal structure: Triclinic. Cleavage: Perfect in two directions. Specific gravity: 2.62 to 2.65.

Hardness: 6 to 6
Luster: Vitreous to pearly

Identified August 2, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous rocks like basalts and granites, as well as metamorphic rocks, through the cooling of magma or hydrothermal processes where plagioclase feldspar grows alongside microscopic reflective mineral platelets.

Uses & applications

Used widely in lapidary arts, wire-wrapped jewelry, carvings, cabochons, and as a collector's specimen.

Geological facts

Sunstone was historically used by ancient Nordic seafarers as a navigational tool (the mythical 'sunstone') to locate the position of the sun on overcast days using polarization of light.

Field identification & locations

Easily identified by its distinctive warm orange body color and the reflective, spangled optical effect (aventurescence) when turned in the light. Commonly found in Norway, Oregon (USA), India, and Russia.