Javan flake obsidian – Java, Indonesia

Snowflake obsidian is a natural volcanic glass known for its distinctive appearance – white or grey "snowflake-like" patterns scattered in a black matrix. These spots are formed by crystals of minerals such as quartz or tridymite, which develop through gradual crystallization within the originally homogeneous obsidian.

Like regular obsidian, snowflake obsidian forms from the rapid cooling of silica-rich lava. This process creates a glassy, amorphous structure without a crystalline lattice. Over time, certain parts of the obsidian begin to crystallize, forming small spherical structures called spherulites. These mineral inclusions appear visually as white or light grey spots resembling snowflakes, hence the name.

Snowflake obsidian typically has a black base color with striking white to grey spots. Its hardness ranges from 5 to 5.5 on the Mohs scale. The structure is glassy and amorphous, though locally disrupted by zones of partial crystallization. This type of obsidian occurs in volcanic areas worldwide and is well known from locations such as Indonesia.