This sample of mcgovernite is displayed in the Smithsonian Museum of Natural History. Mcgovernite is a silicate mineral of magnesium, manganese, zinc and arsenic. It has the composition Mg4Mn9Zn2As2Si2O17(OH)14. The sample at left is about 10 cm across and is from Sterling Hill mine, Ogdenburg, New Jersey. It is described as mcgovernite with franklinite and willemite. The mcgovernite is bronze to brown in color, showing in the patterns on this sample.