Wikipedia
Abenakiite-(Ce)
Abenakiite-(Ce) (IMA1991-054) is a mineral of sodium, cerium, neodymium, lanthanum, praseodymium, thorium, samarium, oxygen, sulfur, carbon, phosphorus, and silicon with a chemical formula NaCe(SiO)(PO)(CO)(SO)O. The silicate groups may be given as the cyclic SiO grouping. The mineral is named after the Abenaki, an Algonquian Indian tribe of New England. Its Mohs scale rating is 4 to 5.