Snowflake obsidian is a form of volcanic glass that features white or grayish ... although it can take on hues of green, brown, and other colors due to impurities. Because of the lack of ...

The most colorful of all may just be rainbow obsidian, which features an array of iridescent colors, including shades of green ... obsidian is both rock and glass. However, this isn’t the ...

They look like small pieces of obsidian, smooth and shiny ... are thought to be pieces of his brain—turned to glass. The discovery, reported in 2020, was exciting because a human brain had ...