igneous
Obsidian (Tumbled Apache Tear)
Volcanic Glass (SiO2)
Hardness: 5-5.5 (Mohs), Color: Translucent black to smoke-grey, Luster: Vitreous/Glassy, Structure: Amorphous (no crystal structure), Cleavage: None (Conchoidal fracture), Specific Gravity: 2.4
- Hardness
- 5-5
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Physical properties
Hardness: 5-5.5 (Mohs), Color: Translucent black to smoke-grey, Luster: Vitreous/Glassy, Structure: Amorphous (no crystal structure), Cleavage: None (Conchoidal fracture), Specific Gravity: 2.4
Formation & geological history
Obsidian forms through the rapid cooling of silica-rich rhyolitic lava, which prevents crystal growth. Apache Tears are specifically rounded nuggets of obsidian found in perlite deposits.
Uses & applications
Used for making jewelry, lapidary art, collection, and historically for sharp tools and weapons due to its ability to hold an edge.
Geological facts
Legend says they were formed from the tears of Apache women mourning for warriors who jumped from a cliff rather than be captured by the US Cavalry. If held up to the light, they are often surprisingly translucent.
Field identification & locations
Identify by its smooth, glassy texture and rounded, pebble-like appearance. Usually found in volcanic regions of the American Southwest, particularly Arizona.
