mineral

Sunstone

Heliolite (Oligoclase or Orthoclase Feldspar), (Ca,Na)(Al,Si)4O8

AI-generated identification · may be incorrect

Hardness: 6-6.5 on Mohs scale; Color: Orange, red, or golden with metallic flashes; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Two directions at nearly 90 degrees; Specific gravity: 2.62-2.67

Hardness: 6-6
Color: Orange, red, or golden with metallic flashes
Luster: Vitreous to pearly

Identified May 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous rocks like basalt or andesite, and occasionally in pegmatites. The metallic 'aventurescence' is caused by tiny plate-like inclusions of hematite, copper, or goethite. Forms in volcanic lava flows or deep-seated plutonic rocks.

Uses & applications

Primarily used as a gemstone for jewelry (rings, pendants, earrings) and as a collector's mineral specimen. High-quality Oregon Sunstone is highly prized for its copper content.

Geological facts

The metallic shimmer is known as aventurescence. Oregon Sunstone is the official state gemstone of Oregon and is unique because its inclusions are pure copper rather than hematite. Ancient Vikings reportedly used sunstones for navigation on cloudy days.

Field identification & locations

Identify by its unique 'schiller' effect or metallic glitter when rotated under light. Common locations include Oregon (USA), Norway, India, Canada, and Russia. Look for feldspar traits with internal reflections.