
mineral
Small polished dark mineral or gemstone fragment
Indeterminate; possibly smoky quartz, obsidian, or dark tourmaline
AI-generated identification · may be incorrectDark brown-black, glossy to resinous surface, apparently rounded or polished; crystal structure, cleavage, hardness, and specific gravity cannot be determined from the image. Approximate hardness could range from 5–7 Mohs depending on composition.
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Physical properties
Dark brown-black, glossy to resinous surface, apparently rounded or polished; crystal structure, cleavage, hardness, and specific gravity cannot be determined from the image. Approximate hardness could range from 5–7 Mohs depending on composition.
Formation & geological history
Likely a natural mineral fragment that has been tumbled or polished; geological age and formation environment cannot be established visually. Possible origins include volcanic glass or silica-rich hydrothermal veins.
Uses & applications
Small polished pieces may be used in jewelry, crafts, or mineral collections. Common material would generally have modest value unless diagnostic testing confirms a desirable gemstone.
Geological facts
The specimen appears to be only a few millimeters across and is partly translucent at the edges, but the image is insufficient for reliable identification.
Field identification & locations
Field identification requires testing streak, hardness, transparency, magnetism, and specific gravity; a close-up under strong light would help distinguish quartz from obsidian or tourmaline. Similar dark specimens occur worldwide, especially in volcanic and hydrothermal regions.
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Septarian Pebble
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