Rock Identifier
Snowflake Obsidian (Spherulitic Obsidian (contains Cristobalite inclusions)) — igneous
igneous

Snowflake Obsidian

Spherulitic Obsidian (contains Cristobalite inclusions)

Hardness: 5-6 (Mohs); Color: Black with white or grey spots; Luster: Vitreous (glassy); Crystal structure: Amorphous (glass); Specific Gravity: 2.3 - 2.6.

Hardness
5-6 (Mohs)
Color
Black with white or grey spots
Luster
Vitreous (glassy)
Identified More igneous

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Hardness: 5-6 (Mohs); Color: Black with white or grey spots; Luster: Vitreous (glassy); Crystal structure: Amorphous (glass); Specific Gravity: 2.3 - 2.6.

Formation & geological history

Formed from rapidly cooling felsic lava where partial crystallization occurs. The \"flakes\" are spherulites of cristobalite (a type of quartz) that grew as the glass cooled. Typically Cenozoic era.

Uses & applications

Used primarily for jewelry (beads, cabochons), ornamental carvings, and by collectors for its unique aesthetic appeal.

Geological facts

Unlike regular obsidian which is purely glass, this variety contains circular needle-like crystals of cristobalite. It is often used in lithotherapy and folklore as a stone of purity.

Field identification & locations

Identified by its distinctive white 'snowflake' patches against a jet black glass background. It is commonly found in areas of past volcanic activity such as Utah, USA or Mexico.