mineral
Tumbled cream-colored stone, likely quartz or chalcedony
Microcrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image
AI-generated identification · may be incorrectSmooth, rounded, opaque cream-white pebble with a dull to weakly waxy luster and no visible grains or cleavage. Expected hardness about 6.5–7 Mohs and specific gravity near 2.6; it may also be a soft limestone pebble if it scratches easily.
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Physical properties
Smooth, rounded, opaque cream-white pebble with a dull to weakly waxy luster and no visible grains or cleavage. Expected hardness about 6.5–7 Mohs and specific gravity near 2.6; it may also be a soft limestone pebble if it scratches easily.
Formation & geological history
Likely naturally water-rounded material or a tumbled specimen. If chalcedony, it formed from silica-rich fluids filling cavities or fractures, commonly in volcanic rocks; if limestone, it formed as carbonate sediment and later lithified.
Uses & applications
Common chalcedony is used for carvings, cabochons, beads, and decorative stone; limestone is used for aggregate and cement. This small piece has little commercial value.
Geological facts
The photograph does not show diagnostic crystal faces, banding, or fossils, so a precise identification is not possible visually. A steel nail should not scratch quartz/chalcedony, whereas limestone is readily scratched.
Field identification & locations
Common possibilities include quartz/chalcedony, milky quartz, limestone, or polished ceramic-like material. The reported Colombian location is compatible with quartz-bearing river gravels and sedimentary pebbles; test hardness and acid reaction for separation.
