mineral

Quartz (Milky/Smoky variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Grayish-white to tan/light brown; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Grayish-white to tan/light brown
Luster: Vitreous (glassy) to greasy

Identified March 29, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Grayish-white to tan/light brown; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling and solidification of silica-rich magma or through hydrothermal precipitation in veins. Quartz is found in almost all geological ages and environments, particularly in igneous rocks like granite or metamorphic rocks like quartzite.

Uses & applications

Used in the manufacture of glass, ceramics, and electronics (due to its piezoelectric properties). In this raw forms, quartz is used for construction aggregate, abrasives, and as a popular specimen for mineral collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it is the primary component of most beach sand. Historical cultures used quartz for tool-making and jewelry.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and characteristic glassy luster on fresh surfaces. It is found globally, notably in mountainous regions and riverbeds. Collectors look for well-formed crystal points, though massive chunks like this are common.

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