3.7" Blue-Green Plumbogummite on Quartz - Yangshuo Mine, China
This is a gorgeous specimen of blue-green, botryoidal plumbogummite that formed over quartz crystals. This mineral association was collected from the Yangshuo Mine that's located in the Guangxi Zhuang Autonomous Region of China.
Plumbogummite is a rare lead phosphate mineral with the chemical formula PbAl3(PO4)2(OH)5•(H2O). It forms in oxidation zones of lead deposits and primarily forms as a botryoidal mass after other minerals. The "plumbo" portion of this mineral's name is derived from the latin word for lead, "plumbum". "Gummi" comes from the gum like appearance that the mineral often displays.
Silicon Dioxide, also known as SiO2 or Quartz, is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich, hot watery solutions called hydrothermal environments, at temperatures between 100°C and 450°C, and usually under very high pressure. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountains forming, and can be hundreds of millions of years old.