Mineral "Snowflake Obsidian"


Mexico, private collection from Sweden.

Obsidian is a naturally occuring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Black is the most common color of obsidian. However, it can also be brown, tan, or green. Rarely, obsidian can be blue, red, orange, or yellow. Ocassionally two colors of obsidian will be swirled together in a single specimen. Snowflake Obsidian gets its name from the tiny white mineral inclusions, cristobalite, that form little snowflakes-like patterns in the dark stone. Obsidian is hard, brittle, and amorphous, it therefore fractures with sharp edges. In the past, it was used to manufacture cutting and piercing tools, and it has been used experimentally as surgical scalpel blades. The manufacture of obsidian tools by humans dates back to the Stone Age. The condition of the sample is good. Age-related wear, fractures and minor cracks may appear. Dirt and dust may exist. Size approx. 6,0cm x 6,6cm x 3,8cm. Total weight c. 158g.