mineral

Milky Quartz with inclusions

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on the Mohs scale; Color: Opaque white to translucent; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Opaque white to translucent
Luster: Vitreous (glassy) to greasy

Identified February 22, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Opaque white to translucent; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in igneous veins or pegmatites; as a water-worn pebble, it indicates secondary transport in a river or coastal environment. Geological age ranges from millions to billions of years depending on the parent rock.

Uses & applications

Industrial use as a source of silica for glass and electronics; common in landscaping, construction aggregate, and as a 'pocket stone' for mineral collectors.

Geological facts

Milky quartz gets its cloudy appearance from tiny microscopic inclusions of gas or liquid trapped during crystal growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage planes. It is frequently found in gravel pits, riverbeds, and mountainous regions worldwide. The dark inclusion is likely a heavy mineral or tourmaline remnant.

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