mineral

Weathered agate or chalcedony nodule

Microcrystalline quartz (SiO₂), likely chalcedony/agate

AI-generated identification · may be incorrect

Small, rounded, opaque-to-translucent specimen with brown, reddish, and gray patches; quartz has Mohs hardness 7, a vitreous to waxy luster, and no cleavage. The image does not show enough detail to confirm banding or identify it more specifically.

Identified September 29, 2026More mineral →

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Physical properties

Formation & geological history

Likely silica deposited in a cavity or fracture and later weathered into a rounded nodule; chalcedony forms in many volcanic and sedimentary settings over geological time.

Uses & applications

Agate and chalcedony are used for beads, cabochons, carvings, and collectibles; this small, unpolished piece appears mainly suited to collecting.

Geological facts

Agate is a banded variety of chalcedony, but not every chalcedony nodule is visibly banded. A close-up or cut surface would help determine whether this specimen has agate bands.

Field identification & locations

Look for hardness near 7, a waxy luster, and conchoidal fracture; common sources include volcanic rocks and gravel deposits worldwide. The pictured specimen is too indistinct for confident identification beyond a possible chalcedony nodule.