mineral

Quartz-rich pebble, possibly milky quartz

Quartz (SiO₂), potentially quartzite if intergrown with other grains

AI-generated identification · may be incorrect

Hardness 7, white to cream, translucent edges, vitreous to dull luster, and no obvious cleavage; likely massive or microcrystalline rather than a well-formed crystal. The rounded shape indicates natural abrasion or tumbling.

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich igneous, hydrothermal, or metamorphic fluids; quartzite forms when sandstone is metamorphosed. Its exact geological age and locality cannot be determined from the photograph.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, construction aggregate, and electronics; attractive pieces are sold as cabinet or lapidary specimens. This small specimen has limited commercial value.

Geological facts

Quartz is one of Earth’s most abundant minerals and has a diagnostic Mohs hardness greater than ordinary steel or window glass. It commonly develops conchoidal fracture rather than cleavage.

Field identification & locations

Field tests include scratching glass but not by a steel knife, checking for conchoidal fracture, and observing translucent margins; a streak test should be white. Common worldwide in veins, pegmatites, sandstones, and metamorphic rocks.