A novelty in Sainte-Marie-aux-Mines (2017). Matrix formed by sulphides, arsenites and arsenates of Co like erythrite, with some crystals, accompanied by several wire to laminar gold aggregates. SEM analysis shows that it is a rich silver gold, variety electrum, unusual. Silver content is similar in all specimens we have analyzed and varies between 20-24% weight.
Under loupe, we can enjoy that some of these gold aggregates are formed by small crystals of octahedral to cubic forms. We can theorize a secondary genesis for this gold-electrum. We have analyzed the matrix of these specimens observing that the bright metallic matrix corresponds to a mixture of cobalt arsenides, probably skutterudite, and other sulphides. We will send all analyzes to the buyer. The gold and electrum in Bou Azer was already described, but the quality of these specimens we offer surpasses what was known.