metamorphic
Quartzite with Quartz Geode / Vug
Crystalline Silicon Dioxide (SiO2) in Metamorphic Host
Hardness: 7 (Mohs scale); Color: White, translucent, to tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65
- Hardness
- 7 (Mohs scale)
- Color
- White, translucent, to tan
- Luster
- Vitreous to waxy
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: White, translucent, to tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65
Formation & geological history
Formed from the metamorphism of quartz-rich sandstone. The crystal pockets (vugs) form when mineral-rich hydrothermal fluids fill cavities in the rock, allowing quartz crystals to grow slowly over thousands to millions of years.
Uses & applications
Informational specimen for collectors, landscaping, and aggregate in construction. High-purity quartz is used in electronics and glass manufacturing.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. This specific specimen shows 'druzy' quartz, where tiny crystals coat a surface, often found in riverbed 'potatoes' or nodules.
Field identification & locations
Identify by its ability to scratch glass and its lack of reaction to acid. Often found in riverbeds or areas with heavy erosion of metamorphic bedrock. Collectors look for the crystalline 'sparkle' inside weathered river stones.
More like this
