mineral

Massive Quartz (Milky or Gray)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale (scratches glass); Color: White, gray, or translucent bluish-white; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale (scratches glass)
Color: White, gray, or translucent bluish-white
Luster: Vitreous to greasy

Identified March 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. Often found in pegmatites or as large veins in various rock formations. It is one of the most abundant minerals and can date back billions of years depending on the parent rock.

Uses & applications

Used in the manufacture of glass, ceramics, and abrasives. High-purity quartz is used in electronics and solar panels. Common specimens are used for landscaping, garden decor, and by amateur rock collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pieces of massive quartz like this are often the core of mountain ranges. It is resistant to both physical and chemical weathering, which is why it often remains as individual stones even after surrounding rock has eroded.

Field identification & locations

Identify in the field by its hardness (it should easily scratch a steel knife or glass) and its conchoidal (curved/shell-like) fracture pattern. Found globally in almost any geological setting, particularly in riverbeds and mountainous outcrops.

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