New data on distribution of indium in ore deposits of Central Kazakhstan

Iron, tin, tungsten, copper, and polymetallic deposits are examined and the paper investigates the mineral distribution of indium in mineral deposits in central Kazakhstan. Indium is a relatively rare element; of the 18 formations examined only five revealed high concentrations of indium. Economic accumulations were discovered only in Early and Late Variscan skarnitic formations with lead-zinc, copper, and bismuth mineralizations. Among the hypogene minerals, indium was found in sulfides, and silicates. Among supergene minerals indium was found only in oxides, carbonates, and silicates. Sphalerites are the principal collector of indium. No connection between the enrichment in indium and the typomorphic peculiarities of different varieties of sphalerites could be established. In mineral deposits with higher indium concentration, a paragenetic connection of this element with tin is noticeable. Regular enrichment of sphalerites in indium would admit as most probable an isomorphous replacement of zinc and bivalent iron by indium. — A.W. Bellais