mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: translucen grey to black; Luster: vitreous (glassy); Crystal Structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: translucen grey to black
Luster: vitreous (glassy)

Identified April 18, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: translucen grey to black; Luster: vitreous (glassy); Crystal Structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in igneous rocks like granite or pegmatites; the smoky color is a result of natural irradiation from surrounding rocks causing internal defects in the crystal lattice of quartz.

Uses & applications

Used primarily in jewelry (faceted or cabochon), as ornamental specimens for collectors, and in metaphysical practices.

Geological facts

The dark color is often caused by the presence of aluminum traces being activated by free radiation. In very dark, opaque varieties, it is referred to as 'Morion'.

Field identification & locations

Identify by its hardness (scratches glass), glass-like luster, and smoky color without distinct layers. Commonly found in Brazil, Madagascar, and the Swiss Alps.