mineral

Milky Quartz with Iron Staining

Quartz (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 8, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal solutions cooling in veins and cavities of host rocks. This specimen likely comes from a pegmatite or hydrothermal vein, with the brown staining caused by secondary oxidation of iron-rich minerals (like limonite or goethite) following its formation.

Uses & applications

Used in the glass industry, as an abrasive, in electronics (due to piezoelectric properties), and as decorative landscape stone. Lower grade specimens like this are primarily for personal collections or garden edging.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear (rock crystal), but microscopic inclusions of gas or liquid trapped during crystal growth create the 'milky' white appearance seen here.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass and stainless steel) and its lack of cleavage. It is found globally, notably in mountainous regions and riverbeds. Look for the distinct conchoidal (shell-like) fracture patterns on broken edges.

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