mineral

Sunstone

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

Hardness: 6-6.5 (Mohs scale); Color: Yellow, orange, or reddish-brown with metallic flashes; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions; Specific gravity: 2.62-2.67

Hardness: 6-6
Color: Yellow, orange, or reddish-brown with metallic flashes
Luster: Vitreous to pearly

Identified March 17, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in igneous rocks (lava flows) or metamorphic environments. The 'schiller' effect comes from copper or hematite inclusions. Geological age varies greatly from Precambrian to Cenozoic depending on the locality.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons and beads) and as a collector's mineral specimen. Some lower grade material is used in decorative carvings.

Geological facts

Also known as 'Heliolite'. In 1987, it was designated as the state gemstone of Oregon, USA, which produces some of the world's most famous transparent copper-bearing specimens.

Field identification & locations

Identify in the field by looking for the 'aventurescence' (metallic glitter) when rotated under light and its characteristic cleavage. Commonly found in Oregon (USA), Norway, India, and Tanzania. Tips for collectors: Check for clarity and the density of copper plate inclusions.