Plaster crystal cluster

Gypsum crystal cluster (foreignly known as Gypsum druse) is a monoclinic crystalline mineral aggregate with calcium sulfate containing water (Ca[SO4]·2H2O) as the main component. It has been recorded in Qinghai Province, Hubei, Yunnan and other places in China. [1-2] [6] Most of the specimens are colorless, transparent or light yellow. The crystal morphology includes plate, prism and other types. It has a glass luster and pearl gloss clectic surface. The characteristics of swallowtail double crystals can be seen, and Mohs hardness 2.