Abenakiite-(Ce)

Abenakiite-(Ce) (or IMA 1991-054) is a mineral of sodium, cerium, neodymium, lanthanum, praseodymium, thorium, samarium, oxygen, sulfur, carbon, phosphorus, and silicon with a chemical formula    Na26 ( Ce, Nd , La , Pr , Th , Sm ) 6 -[ O | S O 2 |( C O 3 ) 6 |( P O 4 ) 6 | Si6 O 18. It is named after the Abenaki, an Algonquian Indian tribe of New England. Its Mohs scale rating is 4 to 5.