Hand-carved arrowheads and jagged spears made of obsidian, a sharp rock formed by volcanic magma, are remnants of vast ...

Snowflake obsidian is a form of volcanic glass ... It appears as a dark glassy rock that’s typically black, although it can take on hues of green, brown, and other colors due to impurities.

Inky black shards of volcanic glass unearthed in Alberta are helping researchers trace the movements of Indigenous people across Western Canada centuries ago. Hand-carved arrowheads and jagged spears ...