igneous and mineral

Obsidian and Phantom Quartz

Volcanic Glass (SiO2 + MgO + Fe3O4) and Crystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Obsidian: Hardness 5-5.5, jet black, vitreous luster, amorphous; Phantom Quartz: Hardness 7, clear with internal 'phantom' growth layers, vitreous, hexagonal system

Identified March 23, 2026More igneous and mineral →

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Physical properties

Obsidian: Hardness 5-5.5, jet black, vitreous luster, amorphous; Phantom Quartz: Hardness 7, clear with internal 'phantom' growth layers, vitreous, hexagonal system

Formation & geological history

Obsidian forms from rapid cooling of felsic lava; Phantom Quartz forms when mineral deposits (chlorite or hematite) coat a crystal surface during a pause in growth, followed by continued quartz formation

Uses & applications

Predominantly used for ornamental jewelry, spiritual healing practices, and gemstone collecting

Geological facts

Obsidian was used in the Stone Age for sharp tools and mirrors. Phantom Quartz is highly prized by collectors as 'ghost' crystals because they visually map the history of the crystal's growth.

Field identification & locations

Identify Obsidian by its conchoidal (shell-like) fracture and smooth glassy surface. Identify Phantom Quartz by looking for translucent 'v' shapes or internal ghost-like inclusions inside a clear bead.