igneous
Snowflake Obsidian
Volcanic Glass (SiO2) with Cristobalite inclusions
Hardness: 5-5.5; Color: Black with grayish-white patches; Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline matrix); Cleavage: None (conchoidal fracture); Specific Gravity: 2.35-2.6
- Hardness
- 5-5
- Color
- Black with grayish-white patches
- Luster
- Vitreous/Glassy
Identified More igneous →
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Physical properties
Hardness: 5-5.5; Color: Black with grayish-white patches; Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline matrix); Cleavage: None (conchoidal fracture); Specific Gravity: 2.35-2.6
Formation & geological history
Formed when felsic lava cools rapidly with minimal crystal growth. The 'snowflakes' are inclusions of the mineral Cristobalite, which form through a process called devitrification of the volcanic glass.
Uses & applications
Used in jewelry (pendants, beads), decorative bowls, figurines, and as a popular palm stone for collectors and spiritual practitioners.
Geological facts
Unlike most rocks, obsidian is technically a mineraloid rather than a mineral because it is a glass and lacks an internal crystalline structure. The 'snowflakes' represent the beginning of the conversion from glass to solid rock.
Field identification & locations
Identify by its characteristic glassy sheen and the distinct white, flower-like radiating patterns against a dark background. It is commonly found in volcanic regions of Utah, Mexico, and Iceland.
