mineral
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale; Color: Milky white to translucent yellowish-tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal (often microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Milky white to translucent yellowish-tan
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 7 on Mohs scale; Color: Milky white to translucent yellowish-tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal (often microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.65
Formation & geological history
Forms through the precipitation of silica-rich fluids in cavities within sedimentary, igneous, or metamorphic rocks. It can also form as a replacement mineral in organic materials like petrified wood.
Uses & applications
Used for lapidary work, decorative landscaping, and historically for stone tools due to its sharp conchoidal fracture. Commonly collected as a pocket stone.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. This specific specimen shows characteristic waxy luster and shell-like (conchoidal) fractures typical of microcrystalline quartz varieties.
Field identification & locations
Identify in the field by its hardness (will scratch glass), lack of cleavage, and smooth, curved fracture surfaces. Found worldwide in nearly every geological environment.
