Wodginite from northeastern Brazil

Abstract

Two varieties of wodginite, Fe-rich and Mn-rich, occur in pegmatites at Seridózinho, Paraiba State, Brazil. The mineral is monoclinic with a=9.46 Å, b=11.43 Å, c=5.12 Å, ß=91°12' (for the Mn-variety). Optical properties, micro-indentation hardness and reflectance values, and electron-microprobe analyses are presented. A discussion of previously published analyses leads to the conclusion that there seem to be two possible systems to fit the analyses of wodginite into a formula.