igneous
Polished silver sheen obsidian heart
Obsidian (volcanic glass), primarily rhyolitic silica-rich glass
AI-generated identification · may be incorrectUsually black with a reflective silver or gray sheen caused by microscopic inclusions or flow structures; vitreous luster, conchoidal fracture, no cleavage, and Mohs hardness about 5–5.5. The heart shape is human-cut and polished.
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Physical properties
Usually black with a reflective silver or gray sheen caused by microscopic inclusions or flow structures; vitreous luster, conchoidal fracture, no cleavage, and Mohs hardness about 5–5.5. The heart shape is human-cut and polished.
Formation & geological history
Forms when silica-rich lava cools so rapidly that crystals cannot develop, generally during Quaternary to recent volcanic eruptions. Common sources include Mexico, the western United States, Armenia, and Iceland.
Uses & applications
Used for ornamental carvings, cabochons, jewelry, display pieces, and historically sharp blades and arrowheads. The polished heart is primarily a decorative or metaphysical collectible.
Geological facts
Obsidian is technically a natural volcanic glass rather than a fully crystalline mineral. Silver sheen varieties reflect light from microscopic gas bubbles, feldspar, or other aligned inclusions.
Field identification & locations
Identify by its glassy appearance, sharp conchoidal edges, lack of visible interlocking crystals, and typical black-to-gray color; it is denser and harder than man-made glass. A locality label or streak/chemical testing helps distinguish it from slag or industrial glass.
