Sunstone
Oligoclase var. Sunstone (Feldspar variety) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Triclinic system; typically found in massive or granular habits, rarely as distinct crystals
Mineral Group
Silicates; Tectosilicate (Feldspar group / Plagioclase series)
Chemical Formula
(Ca,Na)(Al,Si)4O8 with Hematite (Fe2O3) or Goethite inclusions
Formation Process
Igneous formation; crystallizes from cooling magma in plutonic environments or volcanic flows where mineral inclusions deposit within the feldspar lattice
About This Crystal
A translucent to opaque peach-orange stone with a vitreous to pearly luster. It features a characteristic 'shiller' or aventurescence caused by light reflecting off tiny platelike inclusions of hematite, copper, or goethite.
Physical Characteristics
Color: Orange, peach, or reddish-brown with white; Streak: White; Cleavage: Good in two directions at nearly 90 degrees; Fracture: Conchoidal to uneven; Specific Gravity: 2.62–2.65; Fluorescence: Occasionally weak red/orange
Optical Properties
Refractive Index: 1.537–1.547; Birefringence: 0.007–0.010; Optical Phenomenon: Aventurescence (metallic glitter caused by light reflecting from mineral platelets)
Hardness & Durability
Origin Region
Norway (Tvedestrand), India, Canada, USA (Oregon), and Russia; typically found in igneous rocks
Hardness & Durability
Mohs Hardness: 6.0–6.5; Toughness: Poor to fair due to cleavage planes; Wearability: Suitable for jewelry but requires protection from hard knocks
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic and steam cleaners. Store away from harder stones like quartz or sapphire to prevent scratching.
Rarity & Value
Common to uncommon; Oregon Sunstone with copper is highly prized; values increase with the intensity of the schiller effect and clarity of the base material; treatments are rare.
Special Characteristics
Displays 'schiller' or aventurescence; the metallic-looking inclusions create a sparkling effect when the stone is turned under light.
Lore & History
Historically linked to ancient Norse culture as a navigational aid and used by indigenous people of the American Northwest. Traditionally associated with the solar plexus chakra and believed to represent leadership, vitality, and personal power.