mineral

Botryoidal Chalcedony (Desert Rose Agate)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

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 →

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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.