Snowflake Obsidian
Obsidian var. Spherulitic · Semi-Precious Gemstone / Decorative Stone
Crystal System
Amorphous (Non-crystalline glass); Inclusions follow a Radial/Spherulitic habit
Mineral Group
Silicates (Volcanic Glass)
Chemical Formula
SiO2 (70–75%) with inclusions of Cristobalite (SiO2) and various oxides (MgO, Fe3O4)
Formation Process
Igneous/Volcanic. Formed through rapid cooling of high-silica (rhyolitic) lava, preventing crystal growth. The 'snowflakes' form through partial devitrification, where the glass begins to crystallize into cristobalite.
About This Crystal
An opaque, black volcanic glass featuring white or grayish radiating, flower-like patches called spherulites. It has a vitreous (glassy) luster and a smooth, dense texture. The specimen shown has been polished into a double-terminated hexagonal point (wand).
Physical Characteristics
Color: Black with white/gray inclusions; Streak: White; Cleavage: None; Fracture: Conchoidal (shell-like); Specific Gravity: 2.35–2.60; Tenacity: Brittle; Fluorescence: Generally inert.
Optical Properties
Isotropic (Singly Refractive) due to amorphous nature; Refractive Index: 1.48–1.51; Luster: Vitreous; Transparency: Opaque to translucent on thin edges; No pleochroism.
Hardness & Durability
Origin Region
Western United States (Utah, Oregon), Mexico, and Iceland; typically found in areas of geologically recent volcanic activity
Hardness & Durability
Mohs Hardness: 5.0–6.0. It is harder than window glass but softer than quartz. Toughness is low; it is very brittle and prone to chipping or shattering upon impact.
Care & Maintenance
Clean with warm soapy water and a soft cloth. Avoid ultrasonic or steam cleaners as thermal shock can crack the glass. Store separately from harder stones like quartz or topaz to prevent scratching.
Rarity & Value
Common and affordable. Value is determined by the balance and pattern of the snowflake inclusions. Rarely treated as it is naturally abundant.
Special Characteristics
Features devitrification patterns known as spherulitic inclusions of cristobalite, which create the signature 'snowflake' visual effect.
Lore & History
Historically used by ancient cultures for making sharp tools and mirrors. Metaphysically, it is regarded as a stone of purity and balance; traditionally associated with the Root Chakra and believed to help surface hidden patterns and provide protection through grounding.