sedimentary

Botryoidal Chalcedony (Agate)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale. Color: Tan, brown, and translucent orange. Luster: Waxy to vitreous. Crystal Structure: Hexagonal (trigonal) microcrystalline. Features a 'grape-like' or botryoidal surface texture.

Hardness: 6
Color: Tan, brown, and translucent orange
Luster: Waxy to vitreous

Identified July 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater in cavities or veins within volcanic or sedimentary rocks. It often grows in concentric layers around a nucleus.

Uses & applications

Used primarily for lapidary work, jewelry (cabochons), and as a collector's specimen due to its unique bubbly texture.

Geological facts

The term 'botryoidal' comes from the Greek word 'botrys', meaning a cluster of grapes. This specific rounded shape is common in minerals that grow in confined spaces like vugs or pockets.

Field identification & locations

Identify in the field by its distinctive rounded, bubble-like surface and its high hardness (it will scratch glass). Commonly found in desert regions or areas with ancient volcanic activity.