sedimentary

Agatized Fossil (Druzy Agate)

Silicon Dioxide (SiO2) replacing organic matter

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Brown, tan, and translucent amber; Luster: Vitreous to waxy; Texture: Microcrystalline with druzy crystals; Cleavage: None/Conchoidal fracture.

Hardness: 6
Color: Brown, tan, and translucent amber
Luster: Vitreous to waxy

Identified May 13, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brown, tan, and translucent amber; Luster: Vitreous to waxy; Texture: Microcrystalline with druzy crystals; Cleavage: None/Conchoidal fracture.

Formation & geological history

Formed through permineralization where silica-rich groundwater replaces organic structures or fills cavities in sedimentary layers, typically over millions of years (often Jurassic to Eocene).

Uses & applications

Used primarily for lapidary work, jewelry making (cabochons), and as educational or collectible geological specimens.

Geological facts

This specimen shows druzy quartz crystals lining an internal cavity, which is common in agatized fossils where the original biological material has been completely replaced by mineral.

Field identification & locations

Identify by its waxy exterior luster, hardness (won't scratch with a steel knife), and the crystalline interior. Commonly found in riverbeds or eroded sedimentary outcrops.