mineral

Yellow chalcedony (likely lemon-yellow quartz)

Microcrystalline quartz, SiO₂; possibly iron-bearing or heat-treated chalcedony

AI-generated identification · may be incorrect

Smooth, rounded and opaque to slightly translucent, with waxy-to-dull luster and pale lemon-yellow color. Quartz hardness is about 7 Mohs, no obvious cleavage, conchoidal fracture, and specific gravity near 2.6; the surface appears tumbled or naturally water-worn.

Identified September 17, 2026More mineral →

Explore Yellow chalcedony (likely lemon-yellow quartz) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Chalcedony forms when silica-rich groundwater fills cavities and fractures, commonly in volcanic rocks; yellow color may result from iron compounds or treatment. Exact geological age and locality cannot be determined from the photograph.

Uses & applications

Used as a decorative stone, cabochon, bead, or polished collectible; ordinary pieces have limited commercial value.

Geological facts

The image supports identification as a quartz-rich yellow stone, but cannot reliably distinguish chalcedony from yellow jasper, calcite, or dyed material without tests.

Field identification & locations

Check hardness with an inconspicuous area: it should scratch glass if quartz, while calcite will not. Look for translucency at thin edges, conchoidal fracture, and reaction to dilute hydrochloric acid; typical value is about $2-$20, or $20-$75 for attractive polished material.