Snowflake Obsidian
Obsidian (Volcanic Glass) with Cristobalite inclusions · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Amorphous (mineraloid); inclusions are Tetragonal
Mineral Group
Silicate (Igneous Volcanic Glass)
Chemical Formula
SiO2 (approx. 70–75%) + MgO, Fe3O4 and inclusions of SiO2 (Cristobalite)
Formation Process
Extrusive igneous process where high-silica lava cools rapidly, preventing crystal growth; snowflake patterns form via 'devitrification' into cristobalite.
About This Crystal
An opaque, black volcanic glass characterized by white or grayish orbicular 'snowflake' patches. It has a vitreous luster and a smooth, polished surface in this spherical form.
Physical Characteristics
Color: Black with grey/white patches; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.35–2.45; Fluorescence: Generally none.
Optical Properties
Isotropic (singly refractive); Refractive Index: 1.48–1.51; Luster: Vitreous; Transparency: Opaque to occasionally translucent on thin edges.
Hardness & Durability
Origin Region
Utah, USA; Mexico; Iceland; Italy (Lipari Islands)
Hardness & Durability
Mohs Hardness: 5.0–5.5; Toughness: Brittle; sensitive to rapid temperature changes and physical impact.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners and harsh chemicals; store separately to prevent scratching from harder gemstones like quartz.
Rarity & Value
Common; relatively inexpensive; value is determined by the balance and beauty of the 'snowflake' patterns; usually untreated.
Special Characteristics
Features radial clusters of white cristobalite crystals (spherulites) created by the partial crystallization of the glass over geological time.
Lore & History
Historically used for making sharp tools and arrowheads; traditionally viewed as a stone of purity and balance, associated with the Root Chakra in folk healing.