mineral

Tumbled chalcedony (likely agate)

Chalcedony, microcrystalline quartz (SiO₂); banding is not clearly visible to confirm agate

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; cloudy cream-to-gray-brown, waxy luster, translucent edges, and no obvious cleavage. Quartz crystals are microscopic and commonly fibrous; specific gravity is about 2.6.

Identified October 14, 2026More mineral →

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Physical properties

Mohs hardness 6.5–7; cloudy cream-to-gray-brown, waxy luster, translucent edges, and no obvious cleavage. Quartz crystals are microscopic and commonly fibrous; specific gravity is about 2.6.

Formation & geological history

Silica-rich fluids deposited quartz in cavities and fractures, later compacted into chalcedony; the specimen has been tumbled and polished. Formation age cannot be determined from appearance alone.

Uses & applications

Used for beads, jewelry, carvings, and decorative objects; industrial chalcedony is also a silica source.

Geological facts

Chalcedony is a cryptocrystalline variety of quartz. Agate is banded chalcedony, but no distinct bands are apparent here.

Field identification & locations

Look for a smooth waxy sheen, translucency, and hardness sufficient to scratch glass; visible concentric bands would support an agate identification. Chalcedony occurs worldwide in volcanic cavities and sedimentary settings.