igneous

Smoky Quartz on Feldspar (Granite Pegmatite)

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)

Hardness: 6 (Feldspar) to 7 (Quartz); Color: Smoked-grey crystals on tan/orange host rock; Luster: Vitreous to pearly; Crystal structure: Trigonal (quartz) and Monoclinic (feldspar).

Hardness: 6 (Feldspar) to 7 (Quartz)
Color: Smoked-grey crystals on tan/orange host rock
Luster: Vitreous to pearly

Identified March 17, 2026More igneous →

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Physical properties

Hardness: 6 (Feldspar) to 7 (Quartz); Color: Smoked-grey crystals on tan/orange host rock; Luster: Vitreous to pearly; Crystal structure: Trigonal (quartz) and Monoclinic (feldspar).

Formation & geological history

Formed in high-silica magma during the slow cooling and crystallization of igneous intrusions, specifically in pegmatite pockets. Age varies globally from Precambrian to Cenozoic.

Uses & applications

Quartz is used in glassmaking and electronics; feldspar is used in ceramics and glass; high-quality specimens are used for mineral collecting and lapidary arts.

Geological facts

Smoky quartz gets its color from natural irradiation of aluminum-bearing quartz. Darker varieties can be so dark they are opaque, commonly referred to as 'Morion'.

Field identification & locations

Identify by looking for vitreous, smoky grey crystals growing out of a more opaque, blocky orange or white mineral matrix. Common in mountainous regions like the Rockies or Alps.

Other igneous specimens

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Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous

Magnetite

Iron(II,III) oxide (Fe3O4)

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral

Magnetite

Magnetite (Fe3O4)

mineral