Obsidian (Mahogany)
“Volcanic glass with tiger stripes”
Igneous
Mahogany obsidian is a variety of obsidian featuring reddish-brown streaks and swirls caused by microscopic inclusions of iron oxide (hematite). Like all obsidian, it forms from rapidly cooled silica-rich lava but its banded appearance makes it particularly popular in jewelry and lapidary work.
Composition
volcanic glass (SiO₂), hematite inclusions, magnetite
Where Found
Glass Buttes (Oregon, USA), Lipari (Italy), Mexico, Armenia, Japan
Mohs Hardness
5-5.5
Fun Fact
Each flow of mahogany obsidian has a unique chemical fingerprint, allowing archaeologists to trace ancient obsidian tools back to their exact volcanic source.
Test Your Knowledge
How do archaeologists use obsidian's chemical composition to trace ancient trade routes?
Related Specimens
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