mineral

Sunstone (Feldspar)

Plagioclase Feldspar ((Ca, Na)(Al, Si)4O8)

AI-generated identification · may be incorrect

Hardness: 6.0-6.5 (Mohs scale); Color: Peach, orange, or reddish with metallic glints; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Two directions at nearly 90 degrees; Specific gravity: 2.62-2.72.

Hardness: 6
Color: Peach, orange, or reddish with metallic glints
Luster: Vitreous to pearly

Identified April 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous environments, typically cooling from basaltic or andesitic lava flows. The unique 'schiller' effect is caused by tiny hematite or copper inclusions that reflect light as the mineral cools.

Uses & applications

Primarily used as a gemstone in jewelry (rings, pendants, earrings) and as a lapidary material for carvings or decorative items.

Geological facts

The metallic shimmer seen in sunstone is called 'aventurescence'. It was once thought to be used by Viking navigators to locate the sun on cloudy days, though this is often debated between Sunstone and Iceland Spar.

Field identification & locations

Identify in the field by its distinct orange-to-gold metallic 'glitter' or flakes within a translucent to opaque feldspar matrix. Commonly found in Oregon (USA), Norway, Tanzania, and India.