mineral

Quartz with inclusions

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to white with dark inclusions; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to white with dark inclusions
Luster: Vitreous (glassy)

Identified May 31, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to white with dark inclusions; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in rock cavities or during the late stages of igneous crystallization. Quartz is common in almost all geological environments and can be from any geological age.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as semi-precious gemstones in jewelry. Specimens with interesting inclusions are sought after by collectors.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. Variations with dark inclusions are often called rutilated or tourmalinated quartz if the inclusions are specific minerals, though these dark spots appear to be chlorite or carbonaceous material.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Look for the glassy luster and the way it breaks into curved, shell-like surfaces. Found globally in creek beds, mountains, and mines.