Snowflake obsidian is a form of volcanic glass that features white or grayish “snowflake” shapes made of embedded cristobalite. These pretty patterns are not artificially added as a cheap ...

Obsidian is a black volcanic glass; deposits found here were historically used by Indigenous peoples to craft tools. Over 80 plant species in the area have traditional uses in medicine ...

A decade earlier, Rademaker’s advisor, archaeologist Daniel Sandweiss, had made the unexpected discovery of flakes and tools made of obsidian, a volcanic rock, in excavations at one of the oldest ...

referring to the wealth of obsidian deposits in the area, which were formed by ancient lava flows. The dormant Medicine Lake Volcano sits in the middle of the monument and stretches over an area ...