mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Ferruginous Oxides
AI-generated identification · may be incorrectHardness: 7 (Mohs scale); Color: Grayish-white with orange-brown iron spots; Luster: Vitreous to dull; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65
- Hardness
- 7 (Mohs scale)
- Color
- Grayish-white with orange-brown iron spots
- Luster
- Vitreous to dull
Identified More mineral →
Explore Quartz with Iron Staining in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: Grayish-white with orange-brown iron spots; Luster: Vitreous to dull; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65
Formation & geological history
Quartz forms by crystallization from molten magma or precipitation from hot hydrothermal veins. The orange staining is a secondary process where iron-rich water infiltrates micro-cracks and oxidizes over geologic time.
Uses & applications
Commonly used as construction aggregate, in industrial glass making, and for amateur rock collecting. Larger, clearer specimens are used in jewelry.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. The 'rust' spots are often Limonite or Goethite, which are iron oxide minerals.
Field identification & locations
Identify in the field by its ability to scratch glass and its lack of cleavage. Look for the characteristic orange-brown 'stains' that cannot be easily washed off. Commonly found in riverbeds and mountainous terrain.
