mineral

Sunstone

Oligoclase or Andesine (Feldspar Group), (Ca,Na)((Al,Si)4O8)

AI-generated identification · may be incorrect

Hardness: 6–6.5 on the Mohs scale; Color: Orange, reddish-brown, or gold with metallic schiller; Luster: Vitreous to pearly; Crystal structure: Triclinic; Specific gravity: 2.62–2.65.

Hardness: 6–6
Color: Orange, reddish-brown, or gold with metallic schiller
Luster: Vitreous to pearly

Identified March 13, 2026More mineral →

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Physical properties

Hardness: 6–6.5 on the Mohs scale; Color: Orange, reddish-brown, or gold with metallic schiller; Luster: Vitreous to pearly; Crystal structure: Triclinic; Specific gravity: 2.62–2.65.

Formation & geological history

Formed in igneous or metamorphic environments, often crystallizing within basaltic lava flows or pegmatites. The metallic 'glitter' is caused by tiny inclusions of copper or hematite plates following crystal planes.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons and beads) and as a lapidary material for decorative objects or metaphysical collecting.

Geological facts

The optical phenomenon that gives it its sparkle is called 'aventurescence.' It was famously used by Vikings as a 'sunstone' (though this is debated with Iceland Spar) to navigate during cloudy days by detecting polarized light.

Field identification & locations

Identify by its distinctive metallic 'schiller' effect when rotated under light. Commonly found in Oregon (USA), Norway, Tanzania, and India. Collectors should look for rich color and high inclusion density.