
igneous
Apache Tear (Obsidian)
Volcanic Glass (Amorphous SiO2)
Hardness of 5 to 5.5 on the Mohs scale, dark black to smoky brown color, vitreous luster, amorphous crystal structure (no cleavage), specific gravity of approximately 2.35 to 2.40.
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Physical properties
Hardness of 5 to 5.5 on the Mohs scale, dark black to smoky brown color, vitreous luster, amorphous crystal structure (no cleavage), specific gravity of approximately 2.35 to 2.40.
Formation & geological history
Formed from rapidly cooling felsic lava (silica-rich) that does not have time to grow crystals, typically associated with rhyolitic volcanic flows.
Uses & applications
Used in lapidary arts, jewelry making, ornamental carvings, and as a popular collector specimen.
Geological facts
Legend says that Apache Tears are the petrified tears of grieving women whose warriors fell to their deaths during a clash with US cavalry near Superior, Arizona.
Field identification & locations
Found commonly in the western United States, particularly around Superior, Arizona. In the field, it appears as small, rounded nodules embedded in a grey perlite matrix.