mineral

White pebble, likely quartz or calcite

Indeterminate from image; possible microcrystalline quartz (SiO₂) or calcite (CaCO₃)

AI-generated identification · may be incorrect

Small, rounded, smooth, opaque white pebble with a dull-to-waxy luster. Hardness is uncertain: quartz is Mohs 7 and calcite 3; crystal structure and cleavage are not visible.

Identified September 20, 2026More mineral →

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Physical properties

Small, rounded, smooth, opaque white pebble with a dull-to-waxy luster. Hardness is uncertain: quartz is Mohs 7 and calcite 3; crystal structure and cleavage are not visible.

Formation & geological history

Likely naturally water-worn alluvial material, potentially derived from volcanic, metamorphic, or carbonate rocks. The Davao-area setting near 6.4°N, 125.6°E commonly contains river gravels and volcanic-derived materials, but age and exact formation cannot be determined visually.

Uses & applications

As an ordinary pebble it has little commercial use; attractive pieces may be used for crafts, decoration, or simple collecting.

Geological facts

The image cannot distinguish quartz from calcite, marble, porcelain-like rock, or a man-made material. A scratch test and acid test are needed.

Field identification & locations

Test with a steel knife: quartz should resist scratching, while calcite scratches readily. A drop of vinegar or dilute hydrochloric acid that fizzes suggests calcite; no reaction favors quartz, though a coating can interfere.