igneous
Mahogany Obsidian Arrowhead
Obsidian (volcanic glass) with Hematite inclusions
Hardness: 5-5.5 (Mohs); Color: Reddish-brown and black streaks; Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline); Fracture: Conchoidal; Specific Gravity: 2.4
- Hardness
- 5-5
- Color
- Reddish-brown and black streaks
- Luster
- Vitreous/Glassy
Identified More igneous →
Explore Mahogany Obsidian Arrowhead in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-5.5 (Mohs); Color: Reddish-brown and black streaks; Luster: Vitreous/Glassy; Structure: Amorphous (non-crystalline); Fracture: Conchoidal; Specific Gravity: 2.4
Formation & geological history
Formed from the rapid cooling of felsic lava, preventing crystal growth. The mahogany color is caused by the inclusion of magnetite or hematite during the cooling process.
Uses & applications
Historically used for weaponry and tools; currently used in jewelry, ornamental carvings, lapidary arts, and as a collector's item.
Geological facts
Obsidian fractures with extremely sharp edges, historically used for surgical blades. Mahogany obsidian is specifically prized for its 'wood-grain' appearance.
Field identification & locations
Identify in the field by its glassy texture, shell-like (conchoidal) fracture patterns, and lack of visible crystals. Found in volcanic regions like the Western United States, Mexico, and Japan.
