Snowflake Obsidian Tumbled Gemstone

Obsidian is volcanic glass and can form very sharp edges when chipped, so handle broken or knapped pieces with care. It is safe to cleanse briefly under running water.

Snowflake Obsidian begins as obsidian, molten felsic lava cooled so quickly it never had time to crystallize and instead froze into natural volcanic glass. Over time, tiny radial clusters of the mineral cristobalite crystallize within the glass, blooming into the pale gray-white snowflakes that give the stone its name. It forms in volcanic regions around the world, with well-known deposits across the western United States and Mexico.

Snowflake Obsidian is a mineraloid, an amorphous volcanic glass composed largely of silicon dioxide (SiO2), typically around 70 percent, with minor iron and magnesium that give the glass its black body color. The snowflakes are spherulites of cristobalite, a high-temperature silica polymorph that crystallizes as the glass slowly devitrifies. Because it never formed a crystal lattice, obsidian has no cleavage and breaks with a sharp conchoidal fracture. It rates about 5 to 5.5 on the Mohs scale.

• The Aztecs revered obsidian as itztli, sacred to Tezcatlipoca, the Smoking Mirror, polishing it into scrying mirrors for divination and shaping it into ceremonial blades.
• Pliny the Elder recorded the name obsidian, tracing it to a Roman named Obsius said to have found the black glass in Ethiopia, where polished obsidian became some of the ancient world's earliest mirrors.
• In folk tradition the pale flecks of snowflake obsidian were read as light surfacing through darkness, a reminder that clarity can emerge even from the densest stone.