Snowflake Obsidian

Physical Properties

Hardness: 5-5.5 (Mohs scale); Color: Black with white or gray flower-like patches; Luster: Vitreous (glassy); Crystal Structure: Amorphous (non-crystalline) containing radial clusters of Cristobalite; Specific Gravity: 2.35-2.6

Formation & Geological History

Formed when silica-rich lava cools too rapidly for crystal growth to occur, creating glass. The white 'snowflakes' are spherulites of cristobalite, which form during the devitrification process of the volcanic glass.

Uses & Applications

Primarily used for lapidary work, jewelry (beads, cabochons), ornamental carvings, and 'healing' stone markets. Historically used by indigenous peoples for tools and arrowheads.

Geological Facts

Despite being an 'amorphous' glass, the 'snowflakes' are an example of the glass beginning to crystallize over geological time. It is technically metastable and will eventually turn entirely into mineral crystals.

Field Identification & Locations

Identify by its distinct black glassy base and white, radial star-shaped inclusions. It is commonly found in areas of recent volcanic activity, such as the Western United States (Utah, Oregon), Mexico, and Iceland.

Identified on: 4/19/2026

Mode: Standard