mineral

Quartz (Milky/Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with orange/brown iron oxide staining; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous (glassy) to greasy

Identified March 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust and can be found in rocks dating from the Precambrian to the present.

Uses & applications

Used in glassmaking, abrasives, foundry sand, and the hydraulic fracturing industry. High-purity specimens are used in electronics (oscillators) and as gemstones or decorative carvings.

Geological facts

Quartz is piezoelectric, meaning it generates an electric charge when mechanical pressure is applied. The orange staining on this specimen is likely Limonite or Hematite, which are common iron oxide impurities.

Field identification & locations

Identify in the field by its hardness (it should scratch glass),Lack of cleavage, and translucent appearance. It is commonly found in gravel pits, mountain ranges, and stream beds globally. Most common in pegmatites and metamorphic quartzites.