Igneous
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Hardness: 5-5.5 (Mohs scale); Color: Black with white or gray flower-like patterns; Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline glass); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.3 - 2.6.
- Hardness
- 5-5
- Color
- Black with white or gray flower-like patterns
- Luster
- Vitreous/Glassy
Identified More igneous →
Explore Snowflake Obsidian in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-5.5 (Mohs scale); Color: Black with white or gray flower-like patterns; Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline glass); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.3 - 2.6.
Formation & geological history
Formed when felsic lava cools rapidly with minimal crystal growth. The 'snowflakes' are inclusions of the mineral Cristobalite, which form through a process of devitrification. Most specimens are relatively young geologically (Cenozoic era).
Uses & applications
Primarily used in jewelry (cabochons and beads), ornamental carvings, and as a popular semi-precious stone for mineral collectors and metaphysical practices.
Geological facts
Despite having 'crystals' within it (the flakes), the base material is actually a natural volcanic glass. Ancient cultures often used obsidian for surgical blades because it can be fractured to an edge many times sharper than a steel scalpel.
Field identification & locations
Identify by its distinctive white 'snowflake' patches against a jet-black glassy background. It is commonly found in areas of recent volcanic activity such as Iceland, Mexico, and the Western United States (Utah and Oregon). It lacks the sharp transparency of pure obsidian.
