mineral
Dark brown tumbled stone, likely smoky quartz or polished jasper
Uncertain from image; possible quartz, SiO₂, or iron-rich microcrystalline silica (jasper)
AI-generated identification · may be incorrectGlossy wet-looking surface, opaque to slightly translucent edges, dark brown color, and rounded tumbler polish. Quartz has Mohs hardness 7 and vitreous luster; jasper has hardness about 6.5–7, no visible cleavage, and conchoidal fracture.
Identified More mineral →
Explore Dark brown tumbled stone, likely smoky quartz or polished jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Glossy wet-looking surface, opaque to slightly translucent edges, dark brown color, and rounded tumbler polish. Quartz has Mohs hardness 7 and vitreous luster; jasper has hardness about 6.5–7, no visible cleavage, and conchoidal fracture.
Formation & geological history
Smoky quartz forms in silica-rich igneous or hydrothermal environments, while jasper forms from silica-rich sediment or volcanic fluids; ages vary widely from Precambrian to recent. The specimen has been mechanically tumbled and polished.
Uses & applications
Used as a decorative stone, cabochon, lapidary material, or collectible; not generally used for construction in this form.
Geological facts
The image alone cannot reliably distinguish smoky quartz from opaque brown jasper, agate, or glass. A translucent edge, conchoidal fracture, and scratch resistance help identify quartz varieties.
Field identification & locations
Common sources include Brazil, Madagascar, the United States, Uruguay, and India. Check for bubbles or uniform swirls suggesting glass; quartz should scratch ordinary glass, while jasper is typically opaque and granular.
