mineral

Quartz geode

Microcrystalline quartz and drusy quartz (SiO₂), likely in a chalcedony-rich host

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to gray, translucent interior with a sparkling vitreous drusy luster. Quartz is trigonal and has indistinct cleavage, conchoidal fracture; specific gravity about 2.65.

Identified September 15, 2026More mineral →

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Physical properties

Hardness 7 Mohs; white to gray, translucent interior with a sparkling vitreous drusy luster. Quartz is trigonal and has indistinct cleavage, conchoidal fracture; specific gravity about 2.65.

Formation & geological history

Formed when silica-rich groundwater deposited chalcedony and quartz crystals inside a cavity or vesicle, commonly in volcanic rock. The specimen’s precise geological age cannot be determined from the image; geodes range from Paleozoic to Cenozoic.

Uses & applications

Used as a decorative and lapidary specimen, in displays, jewelry, and occasionally as polished slices or bookends. This appears to be a common small commercial geode rather than gem-grade material.

Geological facts

The sparkling surface consists of tiny quartz crystals called drusy. The gray central area may be chalcedony or iron/manganese-stained quartz rather than a separate mineral.

Field identification & locations

Identify by the hollow cavity, botryoidal/chalcedony rind, glassy sparkle, and hardness sufficient to scratch ordinary glass. Common sources include Brazil, Uruguay, Mexico, Morocco, and the United States.