Snowflake Obsidian, one of many varieties of Obsidian is actually not a single mineral, but an igneous rock. It is formed when lava cools extremely quickly, preventing any real crystalization. The snowflake variety shown here has tiny clusters of quartz crystals in patterns throughout the stone which are called cristobalite or high-temperature quartz clusters.

This stone comes from Mexico, New Mexico, Utah, Oregon, and quite a few other locales. Obsidian is sometimes called Volcanic Glass because of its high luster, chemical composition, and its physical characteristics which are much like glass. Its appeal as a gemstone comes from its attractive shiny black color which contrasts nicely with its random pattern of grayish white spherulites. It is generally not a very expensive gemstone.

Because of its similarity to glass, along with its somewhat soft nature compared to other cryptocrystaline gemstones like agate, it has a tendency to chip while cutting, especially on stone edges.