Hg-Cu-Bearing Metal-Sulfide Assemblage in the H3 Chondrite Tieschitz: Important Carriers of Pristine Hg and Possibly Cd-Isotopic Signatures in the Early Solar System

Here we report the study of a unique assemblage consisting of metallic Hg, cinnabar (HgS), native Cu and covellite (CuS) in the matrix of the Tieschitz H3 chondrite [1]. This finding allows for the first time to determine the isotopic abundance of the Hg isotopes both in matrix and chondrules. HgS is also the potential carrier of CdS. CdS should also allow accurate scrutiny of the isotopic signatures of Cd in chondrules and matrix [2, 3]. Hg- and Cu-sulfides occur mostly as alternating layers of cauliflower-like objects. Nanometer-sized native Hg spherules occur in spongy metallic Cu and within HgS and Cusulfides. Native Cu is mostly polycrystalline fine-grained aggregates.