mineral

Sunstone

Aventurine Feldspar (Plagioclase or Oligoclase)

AI-generated identification · may be incorrect

Hardness: 6.0-6.5; Color: Orange, reddish-brown, yellow; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions; Specific gravity: 2.62-2.65

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

Identified July 5, 2026More mineral →

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Physical properties

Hardness: 6.0-6.5; Color: Orange, reddish-brown, yellow; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions; Specific gravity: 2.62-2.65

Formation & geological history

Forms in igneous rocks like basalt and metamorphic environments. The color and schiller effect are caused by tiny inclusions of copper or hematite plates during cooling.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons, beads) and as a collector's specimen due to its unique optical properties.

Geological facts

The optical phenomenon called 'aventurescence' gives sunstone its metallic glitter. It is the official state gemstone of Oregon, USA, which is famous for producing high-quality copper-bearing specimens.

Field identification & locations

Identify by its warm orange hue and distinctive metallic flash (schiller) when rotated under light. Found in Oregon (USA), Norway, Tanzania, and India.