igneous
Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Hardness: 5-5.5 on the Mohs scale, Color: Black with white or grey snowflake-like patches, Luster: Vitreous (glassy), Crystal Structure: Amorphous (non-crystalline), Cleavage: Conchoidal, Specific Gravity: 2.35 - 2.50
- Hardness
- 5-5
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Physical properties
Hardness: 5-5.5 on the Mohs scale, Color: Black with white or grey snowflake-like patches, Luster: Vitreous (glassy), Crystal Structure: Amorphous (non-crystalline), Cleavage: Conchoidal, Specific Gravity: 2.35 - 2.50
Formation & geological history
Formed from felsic lava that cools rapidly with minimal crystal growth, where subsequent partial crystallization allows clusters of cristobalite minerals to grow, creating the distinct snowflake patterns.
Uses & applications
Used widely in ornamental items, tumbled stones, jewelry, and metaphysical practices. Historically used for sharp cutting tools and arrowheads.
Geological facts
The snowflake patterns are actually radial clusters of needle-like crystals of the mineral cristobalite embedded within the dark volcanic glass.
Field identification & locations
Easily identified by its stark black-and-white contrasting snowflake patterns on a smooth, glassy surface. Found globally in regions with volcanic activity such as the USA, Mexico, and Iceland.
