Sunstone
Image: <a href="//commons.wikimedia.org/wiki/User:Ra%27ike" title="User:Ra'ike">Ra'ike</a> (see also: <a href="https://de.wikipedia.org/wiki/Benutzer:Ra%27ike" class="extiw" title="de:Benutzer:Ra'ike">de:Benutzer:Ra'ike</a>) (CC BY 3.0)
Mineral NameSunstone
Chemical Formula(Na,Ca)(Al,Si)AlSi2O8
Mohs Hardness6
Crystal Systemtriclinic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {001}, good on {010}
Fractureuneven
Specific Gravity2.65
Colorspink, orange, red, brown, yellow, colorless
Transparencytransparent
Type LocalityIndia
Mineral GroupSilicates
Usesjewelry, collector
Associated Mineralsquartz, biotite, hornblende
Rarityuncommon
Description
This image shows a tumble-polished, translucent, pinkish-orange sunstone with characteristic sparkling red and orange aventurescence caused by tiny mineral inclusions.
Geological Context
Sunstone, a variety of oligoclase feldspar, typically forms in igneous rocks such as granites, syenites, and diorites, and can also be found in some metamorphic rocks. Its distinctive shimmer is due to inclusions of hematite or goethite.
