mineral

Quartz (Milky/Crystalline variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent/clear; Luster: Vitreous (glassy); Crystal Structure: Trigonal (Hexagonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: White to translucent/clear
Luster: Vitreous (glassy)

Identified March 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to translucent/clear; Luster: Vitreous (glassy); Crystal Structure: Trigonal (Hexagonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling of magma or by hydrothermal activity where silica-rich fluids precipitate in rock cavities. It can range in age from millions to billions of years old across various geological environments.

Uses & applications

Used in the production of glass, ceramics, and electronics (due to piezoelectric properties). In jewelry, it is used for beads and carvings. It is one of the most common specimens for mineral collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, the Greeks believed clear quartz was ice that had frozen so hard it would never melt, hence the name 'krystallos' (ice).

Field identification & locations

Identify by its ability to scratch glass and steel. Look for hexagonal crystal faces and the lack of cleavage. In the field, it is commonly found in granite veins or as pebbles in riverbeds. It is found globally, with major deposits in Brazil and Arkansas, USA.

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