mineral

Rounded chalcedony or milky quartz pebble

Microcrystalline silica, SiO₂ (chalcedony/quartz)

AI-generated identification · may be incorrect

Creamy white to pale honey, translucent, waxy-to-glassy luster, and apparently massive with no visible crystal faces; Mohs hardness about 6.5–7. Specific gravity is approximately 2.6. The rounded shape suggests natural abrasion or tumbling.

Identified September 22, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed when silica-rich groundwater filled a cavity or replaced host material, followed by weathering and transport; the exact geological age cannot be determined visually. Common settings include volcanic cavities, sedimentary beds, and alluvial gravels.

Uses & applications

Used as a lapidary material for cabochons, beads, carvings, and decorative objects; this small specimen has little commercial value unless it displays unusual banding or provenance.

Geological facts

Chalcedony is a cryptocrystalline aggregate of quartz and moganite, while milky quartz is coarser crystalline quartz; a close identification requires translucency, texture, and testing.

Field identification & locations

Look for waxy translucency, conchoidal fracture, and resistance to a steel blade; it should not fizz in dilute acid. Common worldwide, especially in volcanic and river-gravel environments.