mineral

Quartz (Milky/Smoky variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent grey to white; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent grey to white
Luster: Vitreous (glassy) to greasy

Identified March 28, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent grey to white; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It can be found in igneous, metamorphic, and sedimentary environments and is one of the most abundant minerals in the Earth's crust across all geological ages.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), as an abrasive, in construction as an aggregate, and in jewelry or spiritual collecting as 'healing crystals' or 'river stones'.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is colorless, but impurities create varieties like Amethyst (purple) or Citrine (yellow). The specimen shown displays 'milky' and 'smoky' traits caused by microscopic fluid inclusions or natural irradiation.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (H=7) and its lack of cleavage. It is commonly found in river beds, pegmatites, and mountain ranges globally. Collectors should look for its characteristic glassy luster and irregular fracture surfaces.

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