Apache Tear (Black Obsidian)
Obsidian (Volcanic Glass) · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Amorphous (Non-crystalline); lacks a regular internal atomic structure. It commonly occurs in massive or globular forms.
Mineral Group
Silicates; specifically a volcanic glass rather than a true mineral species due to its lack of crystal structure.
Chemical Formula
SiO2 (approx. 70–75%) + MgO, Fe3O4
Formation Process
Igneous. Forms from the rapid cooling of high-silica (rhyolitic) lava, which prevents crystal growth. Apache Tears are weathered nodules of obsidian found in perlite deposits.
About This Crystal
A translucent to opaque black glass with a vitreous (glassy) luster. This specimen is a tumbled or water-worn nodule. It appears deep black but shows smoky transparency when held against a strong light source. It may contain internal flow bands or small inclusions.
Physical Characteristics
Color: Black to dark smoky brown. Streak: White. Cleavage: None. Fracture: Conchoidal (shell-like curves). Specific Gravity: 2.35–2.6. Magnetism: None. Fluorescence: Generally inert.
Optical Properties
Isotropic (singly refractive) due to being amorphous. Refractive Index: 1.48–1.51. It does not exhibit pleochroism or birefringence.
Hardness & Durability
Origin Region
United States (Arizona, New Mexico), Mexico. Found in regions with recent volcanic activity.
Hardness & Durability
Mohs Hardness: 5 to 5.5. It is relatively brittle and sensitive to thermal shock. While suitable for jewelry, it can scratch or chip if struck against harder materials like quartz.
Care & Maintenance
Clean with warm soapy water and a soft cloth. Avoid ultrasonic cleaners and steam cleaners. Store away from harder stones to prevent scratching and avoid extreme temperature changes.
Rarity & Value
Common. Generally affordable. Value is determined by transparency and size. Unlike regular obsidian, the 'Apache Tear' variety is valued for its rounded nodular form and smoky transparency.
Special Characteristics
Displays smoky transparency when backlit. The conchoidal fracture produces extremely sharp edges, which historically allowed for the creation of precision cutting tools.
Lore & History
Historically used by Indigenous peoples for making arrowheads and tools. Legend states they were formed from the tears of Apache women mourning warriors who jumped from a cliff to avoid capture. In metaphysical lore, it is believed to be a stone of grief support and grounding.