Archaeologists have recovered tools manufactured from obsidian - a natural glass formed by quickly cooling lava.
(Archaeologists; have recovered; tools manufactured from obsidian - a natural glass) (tools; manufactured; from obsidian - a natural glass) (obsidian - a natural glass; formed; by quickly cooling lava)
Archaeologists tools obsidian - a natural glass
have recovered manufactured formed
tools manufactured from obsidian - a natural glass
from obsidian - a natural glass
by quickly cooling lava