Zn₂(Fe,Mn)(PO₄)₂.4H₂O

These samples of phosphophyllite are displayed in the Smithsonian Museum of Natural History. Phosphophyllite is a phosphate mineral of zinc, manganese and iron with the composition Zn₂(Fe,Mn)(PO₄)₂.4H₂O. The crystal sample is about 2x4 cm and the gem is 26.9 carats. They are from Potosi', Bolivia.