Sunstone
Feldspar group, Plagioclase series, Oligoclase variety Sunstone · Semi-Precious Gemstone and Collector Mineral
Crystal System
Triclinic, typically found in massive, tabular, or granular habits with well-developed cleavage planes
Mineral Group
Silicates, specifically Tectosilicates (Feldspar group)
Chemical Formula
(Na,Ca)(Al,Si)4O8 with copper (Cu) or hematite (Fe2O3) inclusions
Formation Process
Igneous formation, crystallizing slowly from cooling magma in pegmatites or volcanic rocks where metallic platelets exsolve during cooling
About This Crystal
A polished, tumble-finished stone displaying a warm, brownish-red to peach-orange body color with distinct white linear banding and a characteristic pearly to vitreous luster. Translucent to opaque with visible internal chatoyant-like light reflections.
Physical Characteristics
Color ranges from peach and orange to reddish-brown; white streak; perfect cleavage in two directions at nearly 90 degrees; uneven to conchoidal fracture; specific gravity around 2.64 to 2.68; brittle tenacity; generally non-fluorescent
Optical Properties
Biaxial positive with a refractive index between 1.533 and 1.552; exhibits weak birefringence and strong adularescence or aventurescence caused by light reflecting off microscopic platelets
Hardness & Durability
Origin Region
Notable sources include Oregon (USA), India, Norway, Russia, and Madagascar; typically found in basaltic lava flows and granitic pegmatites
Hardness & Durability
Mohs hardness of 6 to 6.5; fair to good toughness, but susceptible to cleavage breakage upon hard impacts; moderate wearability for jewelry if protected in settings
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic and steam cleaners; store away from harder gemstones to prevent scratching; sensitive to sudden temperature shocks and harsh acids
Rarity & Value
Uncommon to rare depending on clarity, optical effects (aventurescence), and geographic origin (such as Oregon copper-bearing sunstones); values range widely from affordable tumbled stones to high-value collector gemstones; generally untreated
Special Characteristics
Exhibits aventurescence (a spangled or shimmering metallic appearance caused by light reflection from tiny suspended copper or hematite platelets within the feldspar matrix)
Lore & History
Historically associated with the Norse sunstone used for navigation by Vikings to locate the sun on overcast days; widely used in modern crystal healing to represent leadership, vitality, and joy, traditionally linked to the Sacral and Solar Plexus chakras