mineral

Smoky Quartz

Smoky Quartz (SiO2 - Silicon Dioxide with aluminum impurities)

Hardness: 7 on Mohs scale; Color: translucent grey to dark brownish-black (Morion); Luster: vitreous (glassy); Crystal Structure: Trigonal/Hexagonal; Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: translucent grey to dark brownish-black (Morion)
Luster: vitreous (glassy)

Identified March 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous pegmatites and metamorphic hydrothermal veins. The smoky color is created when natural radiation from surrounding rocks activates aluminum impurities within the crystal lattice, causing structural defects called color centers.

Uses & applications

Used in gemstone jewelry (faceted or cabochon), ornamental carvings, crystal healing collections, and historically for early sunglass lenses in 12th century China.

Geological facts

Smoky quartz is the national gem of Scotland, where it is known as 'Cairngorm' after the Cairngorm Mountains. Extremely dark, nearly opaque specimens are referred to as 'Morion'.

Field identification & locations

Identify by its characteristic smoky transparency and hexagonal prism shape. Look for it in quartz-rich veins within granite. Collectors should look for intact crystal terminations (points) and clarity without internal cracks.

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