mineral

Quartz crystal (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Transparent to translucent, pale yellow to honey-colored, vitreous luster, and conchoidal fracture; Mohs hardness 7, hexagonal crystal structure, no true cleavage, and specific gravity about 2.65. The specimen appears naturally terminated or roughly broken, with possible iron-oxide staining or heat coloration.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, and cavities in igneous rocks; many citrine-colored pieces are formed naturally or heat-treated from amethyst. Quartz spans much of geologic time and occurs from ancient crystalline rocks to modern veins.

Uses & applications

Used in jewelry, mineral collecting, abrasives, glass, electronics, and oscillator technology. Small common crystals generally have modest value.

Geological facts

Natural citrine is less common than amethyst, while commercial yellow quartz is often heat-treated. Quartz is one of Earth’s most abundant and chemically durable minerals.

Field identification & locations

Common in Brazil, Madagascar, the United States, and worldwide hydrothermal veins and geodes; identify by hardness, glassy luster, lack of cleavage, and six-sided crystal habit. A scratch test should be avoided on valuable specimens.