mineral
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale. Color: Pale yellow, light brown, tan, to off-white due to iron oxide staining. Luster: Vitreous to dull earthiness on the outer crust. Crystal structure: Trigonal (microcrystalline/druzy quartz aggregates). Cleavage: None. Specific gravity: 2.65.
- Hardness
- 7 on Mohs scale
- Luster
- Vitreous to dull earthiness on the outer crust
Identified More mineral →
Explore Quartz Geode / Druzy Quartz in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale. Color: Pale yellow, light brown, tan, to off-white due to iron oxide staining. Luster: Vitreous to dull earthiness on the outer crust. Crystal structure: Trigonal (microcrystalline/druzy quartz aggregates). Cleavage: None. Specific gravity: 2.65.
Formation & geological history
Formed in cavities within sedimentary rocks (like limestone or shale) or volcanic rocks, where silica-rich hydrothermal fluids percolated over long periods and precipitated quartz crystals inward.
Uses & applications
Used primarily as decorative display specimens, lapidary material, gemstone carving, and popular mineral collection pieces.
Geological facts
Geodes often appear completely nondescript and rough on the outside like ordinary round stones, but contain brilliant sparkling crystal cavities inside or covered druzy surfaces.
Field identification & locations
Identified by its knobby, botryoidal, or bumpy crust topped with tiny sparkling quartz crystal points. Commonly found in sedimentary formations in the Midwestern United States (Iowa, Illinois, Missouri), Mexico, and Brazil.
