mineral

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: White/creamy with reddish-brown iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal prisms); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White/creamy with reddish-brown iron staining
Luster: Vitreous to greasy

Identified April 9, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or igneous crystallization in pegmatites and veins. These specimens can be found in a wide variety of geological ages ranging from millions to billions of years old.

Uses & applications

Used in glassmaking, abrasives, and as a component in concrete. For collectors, it is a primary constituent of crystals and lapidary rough; in electronics it is used for its piezoelectric properties.

Geological facts

Quartz is one of the most abundant minerals on Earth's crust. The reddish-brown crust on this specimen is likely Limonite or Goethite, which are iron oxides that stain the surface of the underlying white quartz.

Field identification & locations

Identify by its ability to easily scratch glass, lack of cleavage, and white-to-clear appearance often buried under orange dirt or stains. It is found globally across all continents in virtually all geological environments.

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