This cummingtonite is from the Morro da Mina Mine, Conselheiro Lafaite in MInas Gerais, Brazil. This mine operates for the recovery of rhodochrosite rhodonite and spessartine. It contains over 30 different minerals including cummingtonite. It is a silicate and an amphibole that contains the elements Mg, Si, O and H. This piece consists of a mat-like cluster of fibrous crystals on a thin rhodonite matrix. They have a copper color a silky chatoyant luster (hard to photo). This piece measures 1 9/16 x 5/8 x 1/4 inches or 37 x 16 x 6 mm.