igneous

Snowflake Obsidian

Obsidian with Cristobalite inclusions (SiO2)

Hardness: 5-5.5 on Mohs scale; Color: Black with white or gray patches; Luster: Vitreous (glassy); Crystal structure: Amorphous (glass); Specific gravity: 2.35-2.6; Cleavage: None (conchoidal fracture).

Hardness: 5-5
Color: Black with white or gray patches
Luster: Vitreous (glassy)

Identified May 25, 2026More igneous →

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Physical properties

Formation & geological history

Formed from rapidly cooling felsic lava where the cooling is too fast for crystal growth, but partially devitrified to form white 'snowflake' inclusions of spherulitic cristobalite.

Uses & applications

Commonly used in jewelry (cabochons, beads), decorative carvings, and as a popular palm stone for collectors and spiritual use.

Geological facts

The 'snowflakes' are actually internal crystals of the mineral cristobalite. It is technically a volcanic glass rather than a true mineral because it lacks a consistent crystalline structure.

Field identification & locations

Identify by its distinctive white radial patches against a jet-black glassy background and sharp conchoidal edges if chipped. Found in volcanic regions including the USA, Mexico, and Iceland.

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Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous

Magnetite

Iron(II,III) oxide (Fe3O4)

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Magnetite

Magnetite (Fe3O4)

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