Sunstone
A plagioclase feldspar (typically oligoclase or andesine) displaying aventurescence — a metallic shimmering or spangling caused by flat metallic inclusions. Oregon sunstone (often andesine-labradorite, RI up to ~1.568) may show red, green, or bicolor zones. Indian sunstone (oligoclase) shows a golden glitter from hematite/goethite platelets. Copper-bearing Oregon sunstones are natural and untreated.
Physical & Optical Properties
Related: Feldspar Varieties
Key Differentiators
- Aventurescence (schiller) — metallic spangling from copper or hematite/goethite platelets
- Feldspar RI (1.537–1.572) and SG (2.62–2.65)
- Biaxial positive — distinct from uniaxial gems
Treatments
- Copper Diffusion ('Congo Sunstone' / 'Red Labradorite')
Price Context
Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.
About Sunstone
A plagioclase feldspar (typically oligoclase or andesine) displaying aventurescence — a metallic shimmering or spangling caused by flat metallic inclusions. Oregon sunstone (often andesine-labradorite, RI up to ~1.568) may show red, green, or bicolor zones. Indian sunstone (oligoclase) shows a golden glitter from hematite/goethite platelets. Copper-bearing Oregon sunstones are natural and untreated.
Identifying a sunstone? GemID walks through these tests in order — RI, SG, fluorescence, and more.
Try GemID Free →