igneous
Obsidian Jewelry Piece
Volcanic Glass (SiO2 + impurities)
Hardness: 5-5.5 (Mohs); Color: Jet black; Luster: Vitreous to sub-adamantine; Structure: Amorphous (non-crystalline); Fracture: Conchoidal (shell-like curves); Specific Gravity: 2.3-2.6
- Hardness
- 5-5
- Color
- Jet black
- Luster
- Vitreous to sub-adamantine
Identified More igneous →
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Physical properties
Hardness: 5-5.5 (Mohs); Color: Jet black; Luster: Vitreous to sub-adamantine; Structure: Amorphous (non-crystalline); Fracture: Conchoidal (shell-like curves); Specific Gravity: 2.3-2.6
Formation & geological history
Formed from extremely rapid cooling of felsic volcanic lava, which prevents the growth of crystals. Predominantly associated with Quaternary and Tertiary volcanic activity.
Uses & applications
Primarily used for high-fashion jewelry, decorative carvings, and historical surgical blades; the most common use today is as a spiritual or metaphysical stone.
Geological facts
Obsidian is found abundantly in the Trans-Mexican Volcanic Belt where the user is located. The ancient Maya and Aztecs highly valued this material, using it for sacrificial mirrors and lethal weapons like the Macuahuitl.
Field identification & locations
Identify by its glassy texture and distinctive razor-sharp conchoidal fracture. Near 103.4°W (Jalisco, Mexico), look for it in volcanic flows near Lake Chapala or Tequila volcano; it is a very common regional find.
