igneous
Snowflake Obsidian
Volcanic Glass with Spherulitic Cristobalite (SiO2)
Hardness: 5-5.5 | Color: black with white/gray spots | Luster: Vitreous (glassy) | Structure: Amorphous (non-crystalline glass) | Fracture: Conchoidal
- Hardness
- 5-5
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Physical properties
Hardness: 5-5.5 | Color: black with white/gray spots | Luster: Vitreous (glassy) | Structure: Amorphous (non-crystalline glass) | Fracture: Conchoidal
Formation & geological history
Formed through the rapid cooling of silica-rich felsic lava. The "snowflakes" are spherulites formed by the devitrifaction of the glass into cristobalite crystals over time.
Uses & applications
Used primarily for jewelry (cabochons, beads), decorative carvings, and in metaphysical collecting. Historically used for sharp tools.
Geological facts
The white 'snowflakes' are actually inclusions of a mineral called cristobalite, which is a high-temperature polymorph of silica.
Field identification & locations
Identifiable by its smooth glassy texture and distinct white floral or snowflake-like patterns against a jet-black background. Found in volcanic regions like Utah and Mexico.
