
mineral
Tumbled quartz-rich stone, possibly smoky quartz or chert
Uncertain; likely microcrystalline quartz, SiO₂
AI-generated identification · may be incorrectSmall polished gray-brown specimen with a waxy to dull luster and rounded edges; quartz has Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The image is insufficient to confirm crystal structure or exact mineral identity.
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Physical properties
Small polished gray-brown specimen with a waxy to dull luster and rounded edges; quartz has Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The image is insufficient to confirm crystal structure or exact mineral identity.
Formation & geological history
If quartz or chert, it formed from silica-rich fluids or sedimentary silica that later lithified; age depends on its source locality and cannot be determined visually. Its smooth shape indicates human tumbling or polishing.
Uses & applications
Common quartz varieties are used as ornamental stones, abrasives, glass and silicon sources; attractive pieces may be used in inexpensive jewelry or collections.
Geological facts
The dark mottling could reflect iron oxides, smoky coloration, or inclusions, but lighting and image resolution prevent reliable identification.
Field identification & locations
Test with a steel file or glass: quartz should scratch glass and resist a steel blade. A streak test, translucency check, and magnified examination would distinguish quartz from jasper, chert, or slag.