mineral

Quartz geode

Quartz (SiO₂), likely drusy/microcrystalline quartz lining a geode cavity

AI-generated identification · may be incorrect

Colorless to milky white crystals with vitreous luster and generally hexagonal crystal structure; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The specimen appears partially polished or naturally broken, exposing a crystal-lined cavity.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits quartz crystals inside gas vesicles or cavities in volcanic rock, commonly basalt; many commercial examples formed during Cenozoic volcanic activity, though age varies by locality. The original host rock is largely obscured in this specimen.

Uses & applications

Used as a decorative specimen, lapidary material, and occasional jewelry component; quartz is also important in glass, electronics, abrasives, and construction products.

Geological facts

The sparkling surface is drusy quartz—many tiny crystals growing together. Quartz is one of Earth’s most abundant minerals and exhibits piezoelectricity when mechanically stressed.

Field identification & locations

Identify by its glassy sparkle, hardness, lack of cleavage, and quartz-like conchoidal fracture; it will scratch ordinary glass but not steel easily. Common sources include Brazil, Uruguay, Mexico, Morocco, and the United States.