
mineral
Quartz geode cluster
Quartz (SiO₂), likely drusy quartz lining a vug or geode
AI-generated identification · may be incorrectWhite to translucent, glassy crystals with sparkling drusy texture; Mohs hardness 7, vitreous luster, trigonal crystal structure, no prominent cleavage, and specific gravity about 2.65. The specimen appears weathered or matrix-attached rather than fully polished.
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Physical properties
White to translucent, glassy crystals with sparkling drusy texture; Mohs hardness 7, vitreous luster, trigonal crystal structure, no prominent cleavage, and specific gravity about 2.65. The specimen appears weathered or matrix-attached rather than fully polished.
Formation & geological history
Silica-rich groundwater deposited quartz crystals inside cavities in volcanic rock or sedimentary material, commonly during hydrothermal or diagenetic activity. The exact geological age cannot be determined from the image; such cavities range from ancient to relatively young.
Uses & applications
Used as a decorative mineral specimen, lapidary material, and source of quartz for ornaments; gem-quality clear crystals may be cut, though this piece is primarily collectible.
Geological facts
Drusy quartz forms a sugar-like coating of tiny crystals and can sparkle strongly under directional light. Quartz is one of Earth’s most abundant and chemically resistant minerals.
Field identification & locations
Identify by its glassy sparkle, hardness, irregular fracture, and inability to scratch it with a steel nail; calcite would be softer and react with dilute acid. Common localities include Brazil, Uruguay, Morocco, Madagascar, and the United States.