mineral

Sunstone (Feldspar)

Plagioclase Feldspar (Na,Ca)(Al,Si)4O8 with inclusions of Hematite/Goethite

AI-generated identification · may be incorrect

Hardness: 6-6.5 (Mohs), Color: Orange, brown, or gold with metallic flashes, Luster: Vitreous to pearly, Crystal structure: Triclinic, Cleavage: Two directions at nearly 90 degrees, Specific gravity: 2.62-2.65

Hardness: 6-6

Identified June 28, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous rocks like basalt or andesite when flows cool. The shimmering effect (aventurescence) is caused by tiny inclusions of minerals like copper or hematite deposited as the crystal cools.

Uses & applications

Primarily used as a gemstone in jewelry such as rings, pendants, and earrings. Also highly valued by mineral collectors for its unique optical properties.

Geological facts

The 'schiller' or glittery effect is known as aventurescence. Some of the most famous and valuable sunstones contain tiny copper inclusions and are found in Oregon, USA.

Field identification & locations

Identify in the field by its distinct orange-to-peach color and the visible 'glitter' when rotated under light. Often found in volcanic environments. Look for the characteristic feldspar cleavage planes.