'Monsmedite', a discredited potassium thallium sulphate mineral from Baia Sprie and its identity with voltaite: The state of the art

摘要

"Monsmedite" was described half a century ago as a new potassium thallium sulphate mineral occurring in Baia Sprie Romania. It was reported to occur as very dark green, morphologically cubic crystals with idealized formula Tl_2O_3.K_2O.8SO_3.15H_2O Many of the data published are close to those of usual voltaite, but the chemical composition and the measured density are clearl; different. Up to now, all samples labelled "monsmedite" in mineral collections (including a co-type specimen of "monsmedite" proved to be usual voltaite with only very minor amounts of thallium. On this basis, and because the original "monsmedite" sampli has gone lost, the Commission on New Minerals and Minerals Names of IMA decided to discredit "monsmedite" as a new minera and to recommend that the name should be reserved for a possible find of a specimen that fulfills the description and chemica composition of "monsmedite".