mineral
Likely tumbled quartz or calcite pebble
Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing
AI-generated identification · may be incorrectSmall rounded, pale peach-white specimen with a dull-to-waxy luster and granular surface. Quartz has Mohs hardness 7, no cleavage, and specific gravity 2.65; calcite is softer (Mohs 3), has perfect rhombohedral cleavage, and specific gravity 2.71.
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Physical properties
Small rounded, pale peach-white specimen with a dull-to-waxy luster and granular surface. Quartz has Mohs hardness 7, no cleavage, and specific gravity 2.65; calcite is softer (Mohs 3), has perfect rhombohedral cleavage, and specific gravity 2.71.
Formation & geological history
Likely a naturally weathered or human-tumbled mineral pebble; quartz commonly forms in igneous and hydrothermal veins, while calcite forms in limestone, cavities, and hydrothermal deposits. The specimen’s geological age cannot be determined visually.
Uses & applications
Used chiefly as a decorative or lapidary stone; quartz is also important in glass, electronics, and abrasives, while calcite is used in cement, lime, and neutralizing acids. This example is mainly a low-cost collectible or craft stone.
Geological facts
A steel knife or glass-scratch test can distinguish them: quartz resists scratching, whereas calcite scratches easily. Vinegar produces weak fizz on calcite but not quartz.
Field identification & locations
Common worldwide in gravel deposits, veins, cavities, and sedimentary rocks; inspect for translucency, cleavage, and hardness. A definitive identification requires hardness, acid, or specific-gravity testing.
