What is Sunstone?


Sunstone is a member of the Feldspar family and is known for its spangled appearance, or sheen, caused by light interacting with tiny plate-like mineral inclusions within the stone. It’s primarily found in Norway, the United States, and India. Sunstone is often used as a gemstone and is a popular choice for jewelry due to its radiant, sun-like inclusions and spiritual significance.

Sunstone is a radiant gemstone known for its glittering, sun-like inclusions. Its warm hues and sparkling appearance make it a popular choice for jewelry and decorative items. The stone is often used in rings, necklaces, and pendants.

Gemstone Properties

Chemical ClassificationInorganic - Silicate (Feldspar)
ColorRanges from orange to brownish-red, often with sparkling inclusions.
LusterVitreous to pearly.
TransparencyTransparent to translucent.
OccurrenceIndia, the United States (Oregon), and Norway.
FormationSunstone forms in magmatic and pegmatitic rock, and can also be found in alluvial deposits.
DiaphaneityTransparent to translucent with aventurescence
CleavagePerfect in one direction
Mohs Hardness6 to 6.5.
Specific Gravity2.63-2.67.
Diagnostic PropertiesAventurescence (sparkling or metallic glitter).
Chemical Composition(Ca,Na)(Si,Al)4O8
PleochroismWeak to distinct, depending on the stone.
Crystal SystemTriclinic (variety of Feldspar)
Optical PropertiesBiaxial (+)
Refractive Index1.525 - 1.548
Birefringence0.008 - 0.010
2V angleMeasured: 50° to 65°
DispersionNot typically noted for sunstone as it's not a key feature of this stone.