igneous
Obsidian Arrowhead
Obsidian (volcanic glass, SiO2 rich)
Hardness: 5-5.5 (Mohs), Color: Translucent smokey black to opaque, Luster: Vitreous/Glassy, Structure: Amorphous (non-crystalline), Fracture: Conchoidal (shell-like curves), Specific Gravity: 2.4
- Hardness
- 5-5
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Physical properties
Hardness: 5-5.5 (Mohs), Color: Translucent smokey black to opaque, Luster: Vitreous/Glassy, Structure: Amorphous (non-crystalline), Fracture: Conchoidal (shell-like curves), Specific Gravity: 2.4
Formation & geological history
Formed through the rapid cooling of silica-rich felsic lava which prevents crystal growth. This specific piece is a cultural artifact (projectile point) worked by humans using flintknapping techniques.
Uses & applications
Historically used for hunting and tools due to its razor-sharp edges. Modernly used in jewelry, surgical scalpels, and as a collectible geological/archaeological artifact.
Geological facts
Obsidian can be fractured to produce an edge much sharper than high-quality steel scalpels. It has been traded across thousands of miles by prehistoric cultures.
Field identification & locations
Identified by its glassy appearance and sharp, scalloped (knapped) edges. Authentic archaeological specimens are usually found in areas with high volcanic activity or known ancient trade routes.
