mineral
Milky quartz-rich rock
Quartz, SiO₂; possibly quartzite or massive vein quartz
AI-generated identification · may be incorrectWhite to gray, opaque, massive texture, and vitreous to dull luster; quartz hardness is Mohs 7, with no cleavage and conchoidal fracture. The dark coating or matrix may be iron/manganese oxides or another host rock.
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Physical properties
White to gray, opaque, massive texture, and vitreous to dull luster; quartz hardness is Mohs 7, with no cleavage and conchoidal fracture. The dark coating or matrix may be iron/manganese oxides or another host rock.
Formation & geological history
Likely formed as hydrothermal vein quartz or recrystallized quartzite; exact age and setting cannot be determined from the photograph. Quartz veins occur in many igneous, metamorphic, and sedimentary terrains.
Uses & applications
Used for silica, glass, ceramics, electronics, and construction aggregate; attractive pieces are collected but this specimen appears low-grade and uncut.
Geological facts
Quartz is one of Earth’s most abundant minerals and commonly forms six-sided crystals, though massive varieties lack visible crystal faces.
Field identification & locations
Test by scratching glass (quartz should scratch it) and checking for the absence of cleavage; a steel knife should not scratch fresh white material. Common worldwide, especially in hydrothermal veins and metamorphic belts.
