mineral

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Usually Mohs hardness 7, vitreous luster, white to colorless appearance, and a trigonal crystal structure. This specimen appears milky or included, with translucent prismatic crystal faces and conchoidal fracture; cleavage is absent or very poor.

Identified August 7, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, cavities, and veins, commonly during igneous or metamorphic activity. Its exact geological age and locality cannot be determined from the image.

Uses & applications

Used in glass, ceramics, abrasives, electronics, and oscillator technology; attractive crystals are collected and occasionally used in jewelry. Common specimens generally have modest commercial value.

Geological facts

Milky quartz contains microscopic fluid inclusions, mineral inclusions, or structural defects that scatter light. Quartz is one of Earth’s most abundant minerals and is a major component of granite, sandstone, and many metamorphic rocks.

Field identification & locations

Identify it by hardness, glassy luster, lack of cleavage, and six-sided prismatic crystal habit; it should scratch ordinary glass but not be scratched by a steel knife. Common localities include Brazil, Madagascar, the Alps, Arkansas, and many hydrothermal vein systems.