mineral

Quartz (Druzy/Crystalline)

Silicon Dioxide (SiO2)

Mohs hardness of 7; milky white to translucent; vitreous (glassy) luster; hexagonal (trigonal) crystal system; no cleavage, conchoidal fracture; specific gravity 2.65.

Identified May 27, 2026More mineral →

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Physical properties

Mohs hardness of 7; milky white to translucent; vitreous (glassy) luster; hexagonal (trigonal) crystal system; no cleavage, conchoidal fracture; specific gravity 2.65.

Formation & geological history

Formed via hydrothermal activity where silica-rich fluids permeate rock cavities and cool or evaporate, allowing crystals to grow. Common in geodes and veins.

Uses & applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), jewelry, and as a popular specimen for mineral collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz'. Large crystal aggregates like this are often called druzy quartz when the crystals are small and sparkling.

Field identification & locations

Identify by its hardness (scratches glass), glassy luster, and lack of cleavage. Found globally in all types of geological environments, frequently near hydrothermal veins.