mineral
Tumbled smoky quartz
Quartz, silicon dioxide (SiO₂), smoky variety
AI-generated identification · may be incorrectPolished, translucent-to-nearly opaque brown-gray pebble with a vitreous luster. Mohs hardness 7; trigonal crystal structure, but a tumbled piece shows no crystal faces or obvious cleavage; specific gravity about 2.65.
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Physical properties
Polished, translucent-to-nearly opaque brown-gray pebble with a vitreous luster. Mohs hardness 7; trigonal crystal structure, but a tumbled piece shows no crystal faces or obvious cleavage; specific gravity about 2.65.
Formation & geological history
Smoky color develops when natural radiation affects trace aluminum in quartz, commonly in granitic pegmatites and hydrothermal veins over geological time. The photograph cannot establish the specimen’s age or source.
Uses & applications
Used in jewelry, carvings, and decorative or collecting specimens; quartz is also important in glassmaking and electronics.
Geological facts
The brown color can range from pale smoky gray to very dark brown or nearly black; heating or irradiation can alter quartz color.
Field identification & locations
The smooth, glossy finish indicates tumbling or polishing. Quartz is common worldwide, including the Pacific Northwest, but this image does not confirm the identification or a local origin.
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Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral