igneous
Snowflake Obsidian
Snowflake Obsidian (Volcanic Glass)
AI-generated identification · may be incorrectHardness: 5-5.5. Color: Black with white 'snowflake' patches. Luster: Vitreous to dull. Crystal structure: Amorphous. Cleavage: None (conchoidal fracture). Specific gravity: 2.35-2.60.
- Hardness
- 5-5
- Color
- Black with white 'snowflake' patches
- Luster
- Vitreous to dull
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Physical properties
Hardness: 5-5.5. Color: Black with white 'snowflake' patches. Luster: Vitreous to dull. Crystal structure: Amorphous. Cleavage: None (conchoidal fracture). Specific gravity: 2.35-2.60.
Formation & geological history
Formed from the rapid cooling of silica-rich felsic lava. The white 'snowflakes' are inclusions of the mineral cristobalite, formed over time through devitrification.
Uses & applications
Used in lapidary arts, jewelry, and ornamental carving.
Geological facts
The 'snowflakes' in snowflake obsidian are a form of devitrification, where the glass slowly crystallizes over geological time.
Field identification & locations
Identified by its distinctive black background with white radial clusters of cristobalite. Commonly found in areas with past volcanic activity, such as the western United States.
