mineral

Milky quartz (likely iron-stained quartz)

Quartz — silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Typically white to translucent gray or honey-colored, with vitreous to waxy luster and no cleavage; Mohs hardness 7, conchoidal fracture, trigonal crystal structure, and specific gravity about 2.65. The specimen appears massive and locally iron-stained, though lighting and surface alteration limit certainty.

Identified August 13, 2026More mineral →

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Physical properties

Formation & geological history

Quartz precipitates from silica-rich hydrothermal fluids, pegmatites, veins, and cavities, or grows during metamorphism; its age depends on the host rock and may range from Precambrian to recent. Iron-oxide inclusions or weathering create the tan-brown coloration.

Uses & applications

Used extensively in glass, electronics, engineered stone, abrasives, and foundry materials; attractive translucent pieces are collected or occasionally cut as ornamental stone. This rough specimen is mainly a teaching or display sample.

Geological facts

Quartz is one of Earth’s most abundant minerals and is highly resistant to weathering. It commonly produces a white streak and can scratch ordinary steel or glass.

Field identification & locations

Identify by hardness, lack of cleavage, glassy appearance, and conchoidal fracture; a streak test, scratch test, and inspection for hexagonal crystal faces help distinguish it from calcite or feldspar. Common worldwide in quartz veins, granites, pegmatites, and metamorphic rocks.