These specimens show a matrix formed by arsenates such as erythrite and associated sulphides and arsenates of cobalt and iron. We can observe on both the presence of arborescent, filiform and laminar gold aggregates. SEM analysis has shown that this is a variety of gold rich in silver (23-24%w): electrum.
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 deposit where the electrum appeared has been totally covered by mine lands, so more samples can not be obtained on the field. A very rich gold-electrum specimen.