Their reward was the discovery of human remains, animal skulls, pottery, obsidian, and the 2,000-year-old serpentine green mask. The human remains are thought to predate the pyramid, highlighting ...

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 ...

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 ...