Snowflake Obsidian

Physical Properties

Hardness: 5-5.5 (Mohs scale), Color: Black with white 'snowflake' patches, Luster: Vitreous, Crystal Structure: Amorphous (non-crystalline glass with crystalline inclusions), Cleavage: None (conchoidal fracture), Specific Gravity: 2.3-2.6

Formation & Geological History

Formed from rapidly cooling felsic lava where cristobalite (a silica polymorph) crystals grow in radial 'snowflake' patterns (spherulites) within the cooling glass. Primarily from the Neogene or Quaternary periods.

Uses & Applications

Commonly used in jewelry (beads, cabochons), ornamental carvings, and by crystal collectors for aesthetic and metaphysical purposes.

Geological Facts

The 'snowflakes' are actually internal crystals of the mineral cristobalite. Unlike most minerals, obsidian is a volcanic glass and is technically metastable, meaning it will eventually devitrify over millions of years.

Field Identification & Locations

Identify in the field by its distinct glass-like feel, conchoidal (shell-like) fracture patterns, and the presence of white patterns against a dark black background. Commonly found in volcanic areas like Utah, USA and parts of Mexico.

Identified on: 4/23/2026

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