It appears as a dark glassy rock that’s typically black, although it can take on hues of green ... artifacts crafted by Native Americans centuries, if not millennia, ago. Indeed, obsidian ...

Also of Green River Formation chert ... At over eight inches long and nearly one and a half pounds, this obsidian piece is the largest artifact in the Fenn Cache. All told, the 56 artifacts ...

Another way to understand past social and economic relations is to track down the origin of the raw materials used to make the artifacts recovered in archaeological sites. Obsidian, formed by the ...