Sunstone
OligoclaseJewelryWiki Editorial·2 sources·Reviewed 2026-08-04
Feldspar full of tiny reflective platelets that flash orange-red as the stone moves — an effect called aventurescence. Oregon sunstone is coloured by microscopic copper, which is unusual enough that it is one of the few gems whose colour and its glitter come from the same inclusions.
Properties
| Property | Value | Authority |
|---|---|---|
| Mohs hardness | 6–6½ [1] | — |
| Specific gravity | 2.63–2.66 [1] | — |
| Chemical formula | Na0.9–0.3Ca0.1–0.3Al1.1–1.3Si2.9–2.7O8 Read from the species entry, Oligoclase. The subscripts are ranges because oligoclase is a plagioclase feldspar — a point on a compositional series rather than a fixed compound. [1] | — |
| Crystal system | Triclinic [1] | — |
| Suitability for daily wear | Moderate. At 6–6½ it is wearable but feldspar has good cleavage, so a knock is a bigger risk than a scratch. [2] | — |
| Care cautions | Avoid ultrasonic cleaners; the cleavage makes vibration a genuine hazard. [2] | — |
Sources
- Handbook of Mineralogy — Mineral Data Publishing / Mineralogical Society of America (Handbook of Mineralogy, Mineral Data Publishing)
- International Gem Society — gemstone articles — International Gem Society (IGS, gemstone information articles (gemsociety.org))