igneous
Weathered quartz-rich pebble
Milky quartz, likely with iron-oxide staining; exact rock type uncertain from image
AI-generated identification · may be incorrectMostly white to tan, translucent in places, with a vitreous-to-dull luster and granular texture. Quartz hardness is Mohs 7, lacks cleavage, and has a specific gravity near 2.65; the rounded shape indicates water abrasion.
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Physical properties
Mostly white to tan, translucent in places, with a vitreous-to-dull luster and granular texture. Quartz hardness is Mohs 7, lacks cleavage, and has a specific gravity near 2.65; the rounded shape indicates water abrasion.
Formation & geological history
Likely a weathered quartz vein fragment or quartz-rich igneous/metamorphic rock, formed when silica crystallized in a vein or cooled in felsic magma, then eroded and transported by water. Its precise geological age cannot be determined visually.
Uses & applications
Common pieces are used as landscaping stone, aggregate, or lapidary material; attractive translucent specimens may be polished, but this example appears low-grade for jewelry.
Geological facts
Brown coloration commonly comes from iron oxides or hydroxides coating fractures and grain boundaries. The apparent “neck” may reflect a natural fracture, fused pebbles, or differential weathering.
Field identification & locations
Test with a steel file or glass: quartz should resist scratching and scratch ordinary glass; it shows no true cleavage and commonly breaks with curved, conchoidal fractures. Quartz-rich pebbles occur widely in streambeds and glacial deposits.
