mineral

Tumbled quartz pebble, likely iron-stained milky quartz

Quartz (SiO₂), possibly with iron-oxide staining

AI-generated identification · may be incorrect

Opaque to translucent cream, tan, and brown with a subdued polished luster; Mohs hardness 7, trigonal crystal structure, no cleavage, and conchoidal fracture. The rounded, smooth surface suggests tumbling or natural water-wear.

Identified October 16, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich fluids and occurs in many rock types and veins; iron oxides can stain it brown. Quartz formed throughout geologic history, and the pebble was later rounded by water or mechanical tumbling.

Uses & applications

Commonly used for lapidary crafts, jewelry, decoration, and mineral collecting; quartz is also important in glassmaking and electronics.

Geological facts

Quartz is one of Earth’s most abundant minerals and resists scratching better than most common minerals.

Field identification & locations

Identify by its glassy-to-waxy appearance, hardness, and lack of cleavage; a scratch test against glass can help, though this specimen’s exact variety cannot be confirmed visually. Quartz pebbles occur worldwide in river gravels and many geological settings.