Assertion: obsidian | /r/MadeOf | about 70 percent
Facets:
Source sentences:
text: Obsidian consists of about 70 percent or more non-crystallized silica (silicon dioxide).
text: Obsidian consists of about 70 percent or more non-crystallized silica (silicon dioxide).
text: Obsidian consists of about 70 percent or more non-crystallized silica (silicon dioxide).