sedimentary

Druzy Quartz on Limestone

Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 7 (Quartz) / 3 (Limestone); Color: Grayish-tan host rock with honey-orange and clear crystals; Luster: Vitreous/sparkly (Quartz) to earthy (Limestone); Structure: Micro-crystalline quartz coating voids.

Hardness: 7 (Quartz) / 3 (Limestone)
Color: Grayish-tan host rock with honey-orange and clear crystals
Luster: Vitreous/sparkly (Quartz) to earthy (Limestone)

Identified July 12, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through secondary mineralization where silica-rich fluids circulated through cavities (vugs) in limestone bedrock and precipitated as quartz crystals. The orange color is likely due to iron oxide staining (limonite).

Uses & applications

Primarily of interest to mineral collectors and hobbyists. Limestone host rock is used in construction and agriculture.

Geological facts

The term 'druzy' refers to a coating of fine crystals on a rock surface. The orange-yellow tint in this specimen is a common result of groundwater carrying iron minerals into the rock cavities after the quartz formed.

Field identification & locations

Identify by looking for small, sparkling crystal faces inside rock cavities. Common in karst topography and limestone quarries. Use a drop of vinegar on the host rock; if it fizzes, it is limestone or dolostone.