Testibiopalladite, PdSbTe: A Valid Mineral and Sb-Analogue of Michenerite

Abstract

Abstract Testibiopalladite was reported from two unnamed deposits in China by Anonymous (1974) to be ideally PdSbTe. The description of the mineral included an indexed X-ray powder diffraction pattern, space group determination, electron probe micro-analyses, reflectance, and micro-indentation hardness measurements. This description was published without prior submission to the IMA, which was the norm at the time before China became a member. It is unknown as to why the Commission for New Minerals and Mineral Names (CMNMN) did not examine and vote on the mineral as had been done for all other Chinese mineral descriptions published at the time. It is surprising because the chairman of the CMNMN at the time had reviewed the mineral (Fleischer et al. 1976) and concluded it was a valid species, i.e., the Sb analogue of michenerite (PdBiTe). Further, the same article included a description of “hexastibiopanickelite” which was voted on and rejected by the CMNMN in 1976. From 1981 to 2021 there were many papers published reporting testibiopalladite from several deposits in different countries (e.g., Hudson et al. 1978, Chen et al., 1993, Stepanets et al. 2019, 2020), as well as a single-crystal structure analysis of synthetic PdSbTe which confirmed the assigned space group (Foecker & Jeitschko 2001). The published data (e.g., Barkov et al. 2002, Liang et al. 2019, 2023) suggest that testibiopalladite is a valid mineral species, ideally PdSbTe, and is the Sb analogue of michenerite, PdBiTe, both crystallizing in space group P213. Both the name testibiopalladite and the mineral, ideally PdSbTe, were approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (CNMNC-IMA), Nomenclature Voting Proposal 23-H. Liang et al. (2019, 2023) studied samples from the type locality (Yangliuping deposit, PRC) that are to be considered as a neotype.