mineral

Milky quartz (iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Usually white to translucent with a vitreous-to-waxy luster; hardness 7 on the Mohs scale, no cleavage, conchoidal fracture, and hexagonal crystal structure. The yellow-orange surface staining is likely iron oxides/hydroxides; exact identification is limited by the photograph.

Identified August 17, 2026More mineral →

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Physical properties

Formation & geological history

Quartz commonly crystallizes from silica-rich hydrothermal fluids, pegmatites, and cavities in igneous or metamorphic rocks; it may be Precambrian to recent in age. The surrounding dark host appears consistent with a weathered metamorphic or igneous rock, but cannot be classified confidently from the image.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, engineered stone, and electronics; attractive pieces are collected or cut as decorative material. This rough specimen has modest commercial value.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical potential when mechanically stressed.

Field identification & locations

Identify by its glassy appearance, lack of cleavage, conchoidal fracture, and ability to scratch ordinary glass; iron staining commonly produces yellow, orange, or brown patches. Common worldwide, especially in quartz veins, pegmatites, and hydrothermal deposits.