mineral

Sunstone (Feldspar)

(Ca,Na)((Al,Si)2Si2O8) with inclusions of Hematite or Goethite

AI-generated identification · may be incorrect

Hardness: 6-6.5 (Mohs scale); Color: Orange, reddish-brown, or yellow; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Good in two directions; specific gravity: 2.62-2.67; Notable for its schiller or aventurescence.

Hardness: 6-6
Color: Orange, reddish-brown, or yellow
Luster: Vitreous to pearly

Identified July 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous rocks like basalt or rhyolite, or in metamorphic pegmatites. The aventurescence is caused by tiny plate-like inclusions of copper or iron-oxide minerals during the cooling process.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons and faceted stones) and as a collector's mineral specimen.

Geological facts

Oregon Sunstone is unique because its inclusions are tiny copper flakes, often giving it a green or red 'shiller' effect. It was named the official state gemstone of Oregon in 1987.

Field identification & locations

Identified by its distinctive sparkly reflectance (aventurescence) when turned in the light. Common locations include Oregon (USA), Norway, Tanzania, and India. Collectors look for clarity and the intensity of the metallic flash.