Quartz, SiO2 (Silicon Dioxide), is a widely found rock-building material found in many shapes and forms. It is one of the most commonly used materials by people, having uses in glass manufacture, electronic equipment, jewelry, decoration and in ancient days for producing sparks to start fires.

Description: An unusual Quartz specimen consisting of a botryoidal mass of mineral. Rounded masses rather than sharp-edged crystals. Water erosion is discounted by a fine dust of Calcite covering the Quartz. It is likely that the Quartz is a pseudomorph taking on the shape of a cavity left by some earlier mineral species. The shape of the largest crystal suggests Calcite.

Location: Frazer's Hush Mine, Weardale, Co Durham, England.