igneous

Snowflake Obsidian

Obsidian (volcanic glass) with Cristobalite inclusions

Hardness: 5-5.5 on Mohs scale; Color: Black with white to grayish 'snowflake' patches; Luster: Vitreous (glassy); Crystal Structure: Amorphous (non-crystalline) with crystalline spherulites; Cleavage: None (conchoidal fracture); Specific Gravity: 2.35-2.6.

Hardness: 5-5
Color: Black with white to grayish 'snowflake' patches
Luster: Vitreous (glassy)

Identified March 22, 2026More igneous →

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Physical properties

Formation & geological history

Formed from rapidly cooling felsic lava where water and gas are present. The 'snowflakes' are formed by the process of devitrification, where the amorphous glass begins to crystallize into radiates of cristobalite spherulites. Found in volcanic regions ranging from the Tertiary to Holocene periods.

Uses & applications

Primarily used for jewelry (cabochons, beads), decorative carvings, and as a popular lapidary material for hobbyists and collectors.

Geological facts

Obsidians have been used since prehistoric times to make razor-sharp tools and weapons. Snowflake obsidian is unique because it represents the 'un-making' of a glass as it slowly attempts to turn into stable crystals over geological time.

Field identification & locations

Identify in the field by its distinct glass-like shell-shaped (conchoidal) fractures and the presence of white, star-shaped patterns on a black background. Commonly found in volcanic areas such as the Western United States (Utah, Oregon), Mexico, and Iceland.

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