Gorgeous, 4.1" Botryoidal Chalcedony Formation - Morocco

This is a beautiful geode section that contains a botryoidal chalcedony formation within the cavity. It was collected from the Atlas Mountains of Sidi Rahal, Morocco.

Quartz is the name given to silicon dioxide (SiO2) and is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich environments--usually igneous rocks or hydrothermal environments like geothermal waters--at temperatures between 100°C and 450°C, and usually under very high pressure. In either case, crystals will precipitate as temperatures cool, just as ice gradually forms when water freezes. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountain formation: these veins can be hundreds of millions of years old.
Quartz var. Chalcedony
Sidi Rahal, Atlas mountains, El Kelaa des Sraghna province, Morocco
4.1 x 2.2"