mineral

Botryoidal Chalcedony (Desert Rose Agate)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale), Color: White, gray, or pale blue, Luster: Waxy to vitreous, Crystal Structure: Hexagonal (cryptocrystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.58-2.64

Hardness: 6

Identified June 29, 2026More mineral →

Explore Botryoidal Chalcedony (Desert Rose Agate) 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

Formed from the slow deposition of silica-rich fluids in volcanic cavities (vugs) or sedimentary fissures. The botryoidal (grape-like) shape occurs when silica minerals build up in concentric layers around multiple nuclei.

Uses & applications

Used primarily in lapidary work for cabochons, metaphysical collecting, and as decorative ornamental stone. In industry, high-purity silica is used in optics and electronics.

Geological facts

This bubbly texture is called 'botryoidal,' derived from the Greek word for a cluster of grapes. Chalcedony is often found in the desert and is sometimes referred to as 'desert rose' when it forms these flower-like clusters of rounded lobes.

Field identification & locations

Identify in the field by its distinctive bubbly or 'melted candle wax' appearance and high hardness (it will scratch glass). Commonly found in the American Southwest, Morocco, and Brazil. Collectors look for translucency and lack of fractures.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock