igneous
Snowflake Obsidian
Volcanic glass containing Spherulitic inclusions (SiO2 + impurities)
Hardness: 5-5.5 (Mohs), Color: Black with white or gray patches, Luster: Vitreous/Glassy, Crystal Structure: Amorphous (glass), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.35-2.6
- Hardness
- 5-5
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Physical properties
Hardness: 5-5.5 (Mohs), Color: Black with white or gray patches, Luster: Vitreous/Glassy, Crystal Structure: Amorphous (glass), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.35-2.6
Formation & geological history
Formed through the rapid cooling of felsic lava, which prevents large crystal growth. The 'snowflakes' are inclusions of cristobalite (a polymorph of silica) that grew in the glass during the cooling process.
Uses & applications
Primarily used in jewelry, decorative carvings, beads, and as a popular specimen for rock collectors and metaphysical enthusiasts.
Geological facts
Unlike regular obsidian, Snowflake Obsidian has started a process of 'devitrification' where parts of the glass have transformed into a crystalline mineral. It is often referred to as a stone of purity and balance.
Field identification & locations
Identify by its distinct white, needle-like mineral patterns against a dark black glassy background. Common locations include Utah, USA, and various volcanic regions in Mexico and Iceland.
