mineral

Agate Geode with Quartz Druzy

Chalcedony (SiO2) and Quartz (SiO2)

Hardness: 6.5-7.0 (Mohs scale); Color: Pale blue to translucent grey bands with clear/white internal crystals; Luster: Waxy (agate) to Vitreous (crystals); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.58-2.64.

Hardness: 6
Luster: Waxy (agate) to Vitreous (crystals)

Identified February 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the hollow filling of vesicles (gas bubbles) in volcanic rock or cavities in sedimentary rock. Silica-rich groundwater seeps into the void, depositing layers of microcrystalline chalcedony (agate) followed by macrocrystalline quartz over thousands of years.

Uses & applications

Used primarily for ornamental purposes, lapidary arts (cabochons), jewelry, and as a popular specimen for mineral collectors and educational displays.

Geological facts

Agate geodes are essentially 'bottled time' of ancient hydro-thermal activity. The term 'druzy' refers to the tiny, glittering crystals that coat the inner surface of the geode cavity, creating a shimmering effect.

Field identification & locations

Identify by looking for a bumpy, dull exterior (the host rock) that when broken reveals colorful, translucent concentric banding and a crystalline center. Commonly found in Brazil, Uruguay, and the United States (western states like Oregon and Arizona).

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