igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)

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

Hardness: 5-5
Color: Black with grayish-white 'snowflake' patches
Luster: Vitreous/Glassy

Identified March 15, 2026More igneous →

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Physical properties

Formation & geological history

Formed through the rapid cooling of silica-rich felsic lava. The 'snowflakes' are inclusions of the mineral cristobalite (a type of quartz) that formed as the glass began to devitrify over time. Most specimens are from the Neogene or Quaternary periods.

Uses & applications

Commonly used in jewelry (cabochons, beads), decorative carvings, meditation stones, and as a collector's mineral due to its unique aesthetics.

Geological facts

While regular obsidian is considered a volcanic glass, the white patches in Snowflake Obsidian represent the 'death' of the glass, as it is slowly crystallizing into quartz minerals. Historically, obsidian was used by indigenous peoples for extremely sharp cutting tools and arrowheads.

Field identification & locations

Identify by its distinctive white radial 'snowflake' patterns against a jet-black glassy background. It is found in volcanic regions, notably in Utah (USA), Mexico, and Iceland. In the field, look for smooth, glassy textures and sharp, curved edges on broken pieces.

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