Genplesite is a very rare tin mineral coming from the Oktyabr'skoe deposit in the Noril'sk area, Russia, which is known for nickel and platinum group elements minerals. Its chemical formula is Ca<sub>3</sub>Sn(SO<sub>4</sub>)<sub>2</sub>(OH)<sub>6</sub>â¢3H<sub>2</sub>O. Genplesite is a member of the fleischerite group, and it is a calcium and tin-analogue of fleischerite. It is hexagonal, with space group P6<sub>3</sub>/mmc.