Chalcedony

Fine-grained silica made up of tiny quartz-related crystallites.

Colors & patterns

Often softly translucent white, gray or blue; the wider family includes many colored varieties.

Typical origins

Found worldwide, including Brazil, India, Namibia and Turkey.

Hardness

6.5–7 on the Mohs scale.

Choosing & setting this material

Its even texture and gentle glow make it a classic cabochon material. Dyed colors are available, so appearance alone does not establish natural color.

Care & cleaning

Clean gently with lukewarm water, a little mild soap and a soft cloth, then dry. Avoid steam, ultrasonic cleaners, harsh chemicals and sudden temperature changes, especially when treatments are unknown.

Origins above describe typical sources of the material, not the origin of an illustrated or stocked stone. Hardness measures scratch resistance, not resistance to breaking. Confirm the identity and treatments of the actual piece.

Ask about a custom chalcedony cabochon ↗Explore all 59 materials

Further reading: Material reference · GIA: gem treatments