igneous

Snowflake Obsidian

Volcanic glass with Phenocrysts (SiO2 with Cristobalite inclusions)

Hardness: 5-5.5 on Mohs scale; Color: Black with white or gray 'snowflake' patches; Luster: Vitreous (glassy); Crystal structure: Amorphous (glass) with spherulitic cristobalite; Cleavage: None (conchoidal fracture); Specific gravity: 2.3-2.6

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

Identified March 25, 2026More igneous →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed through the rapid cooling of felsic (silica-rich) lava. The 'snowflakes' are formed as the glass begins to devitrify, creating radiating clusters of white cristobalite crystals within the dark glass matrix.

Uses & applications

Used primarily in jewelry (beads, cabochons), ornamental carvings, and as a popular specimen for rock collectors and metaphysical practitioners.

Geological facts

While regular obsidian is purely glass, Snowflake Obsidian is unique because it shows the early stages of a process where glass turns back into crystal. It was historically used by indigenous cultures to craft sharp tools and arrowheads.

Field identification & locations

Identify by its distinct black base and white, blotchy 'flower-like' patterns. It is commonly found in volcanic regions of the Western United States (Utah, California), Mexico, and Iceland. For collectors, look for high contrast between the black and white areas.

Other igneous specimens

See all

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

Dark Igneous Rock (Likely Basalt or Diabase)

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)

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral

Magnetite

Magnetite (Fe3O4)

mineral