igneous
Obsidian (Apache Tear)
Amorphous Volcanic Glass (SiO2 + impurities)
Hardness: 5.0-5.5; Color: Black, deep smoky brown (transparent when held to light); Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline); Fracture: Conchoidal; Specific Gravity: 2.35-2.6
- Hardness
- 5
- Color
- Black, deep smoky brown (transparent when held to light)
- Luster
- Vitreous/Glassy
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Physical properties
Hardness: 5.0-5.5; Color: Black, deep smoky brown (transparent when held to light); Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline); Fracture: Conchoidal; Specific Gravity: 2.35-2.6
Formation & geological history
Formed from the rapid cooling of high-silica rhyolitic lava. These specific rounded nodules, known as Apache Tears, are found embedded within perlite beds, having cooled at a rate that prevented crystallization but under conditions that allowed them to weather into spherical shapes.
Uses & applications
Used in gemstone collecting, jewelry (beads and pendants), and metaphysical practices. Historically, obsidian was used for making sharp blades and arrowheads.
Geological facts
Legend says that the widows of Apache warriors who were driven off a cliff by U.S. cavalry in the 1870s cried so many tears that they turned into these black stones upon hitting the ground.
Field identification & locations
Identify by its glassy texture, translucent edges when backlit, and smooth conchoidal fracture. Common in the American Southwest, particularly Arizona and New Mexico. Collectors look for high translucency (smokiness) when held to light.
