mineral

Milky quartz (rough quartz crystal)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Typically Mohs hardness 7, white to translucent, with a vitreous luster and hexagonal crystal structure; it has indistinct cleavage and conchoidal fracture. The specimen appears massive to irregularly crystalline, with iron staining or warm lighting producing its yellowish tone.

Identified August 19, 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; individual crystals may range from Precambrian to recent. Exact locality and age cannot be determined from the image.

Uses & applications

Used for glass, electronics, abrasives, engineered stone, and ornamental specimens; attractive transparent pieces may be cut as gemstones.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, generating an electrical charge under pressure.

Field identification & locations

Identify by its glassy luster, lack of obvious cleavage, hardness sufficient to scratch ordinary glass, and six-sided crystal forms when developed. Common worldwide, especially in Brazil, Madagascar, the United States, and Alpine regions.