mineral

Likely tumbled quartz or calcite fragment

Probably quartz (SiO₂) or calcite (CaCO₃)

AI-generated identification · may be incorrect

Small off-white, translucent-to-opaque rounded fragment with a dull to weakly waxy luster and tiny dark inclusions. Quartz has Mohs hardness 7 and no cleavage; calcite has hardness 3, prominent rhombohedral cleavage, and fizzes in dilute hydrochloric acid.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

Could be a naturally weathered or human-tumbled mineral fragment; its geological age and source cannot be determined from the image. Quartz commonly forms in igneous, metamorphic, and hydrothermal rocks, while calcite commonly forms in limestones and veins.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, electronics, and inexpensive lapidary items; calcite is used in cement, lime, aggregate, and ornamental stone.

Geological facts

The image is insufficient for a confident identification because the specimen is partly obscured and lacks visible crystal faces. A hardness test and acid test would distinguish the leading possibilities.

Field identification & locations

Check streak, transparency, cleavage, and hardness: quartz should not scratch with a steel knife, whereas calcite scratches easily and effervesces with acid. Common examples have little collector value unless unusually clear or well formed.