mineral

Likely tumbled quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires hardness and acid tests

AI-generated identification · may be incorrect

Creamy-white, rounded, opaque to slightly translucent, with a dull to waxy luster. Quartz has Mohs hardness 7 and no cleavage; calcite has hardness 3, prominent rhombohedral cleavage, and effervesces in dilute hydrochloric acid.

Identified August 25, 2026More mineral →

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At a glance

Common name: Likely tumbled quartz or calcite
Scientific name: Quartz (SiO₂) or calcite (CaCO₃); exact identification requires hardness and acid tests
Category: mineral
Identified: August 25, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a common tumbled or unidentified specimen; more if confirmed as an attractive, unusually colored, or collectible variety.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

A naturally formed mineral fragment later smoothed by tumbling or abrasion; quartz commonly crystallizes in igneous and hydrothermal settings, while calcite forms in sedimentary environments and veins. Geological age cannot be determined from the image.

Uses & applications

Quartz is used in glass, electronics, abrasives, and ornaments; calcite is used in cement, lime, aggregate, and decorative stone. This specimen has modest decorative or educational value.

Geological facts

The image alone cannot reliably distinguish quartz from calcite or other pale minerals such as feldspar. A steel nail scratches calcite but not quartz; glass scratches quartz.

Field identification & locations

Common sources include quartz veins, pegmatites, limestone, and marble deposits worldwide. Test on an inconspicuous area: hardness, cleavage, and dilute acid response are diagnostic.