Calcite with Siderite

Item Description

Please note that this specimen is labeled as Calcite with Sphalerite from the San Martín Mine in Mexico, but I'm very confident that the tabular crystals are Siderite, which is not reported from this locality according to the entry on mindat.org. With that said, it's a beautiful association specimen for a mine which is well-known to have produced a wide number of styles/habits of Calcite over the years. Many vitreous, silvery-white colored modified trigonal Calcite crystals measuring up to 1.6 cm at the longest dimension are associated with compressed "disc"-like crystals of what is almost certainly Siderite, showing a bronzy, almost pseudo-metallic quality on the surface, measuring up to 1.3 cm across. On the underside of the specimen, brassy metallic Chalcopyrite and grey-black Sphalerite can also be seen. The crystals are beautiful up close and the Siderites are striking both in their form and color. A really interesting and unusual association specimen that honestly doesn't look like any other Calcite/Siderite specimen I can remember seeing from another locality.
From the collection of Kurt Hefendehl (#41 MX), a well-known German collector all over Europe with worldwide contacts to dealers and collectors. He started collecting seriously at the age of 14 and his great and varied worldwide collection reached over 6000 pieces. He was very active mineralogically until shortly before his passing in 2020 at the age of 82. Considering his collection had a large number of pieces, it still had an unusually high standard of quality from most worldwide localities. He particularly specialized in all classics as well as minerals of the Black Forest, where he spent much time collecting. His Black Forest and German subcollections went to his good friend Wolfgang Wendel. We at The Arkenstone have the privilege of offering the remainder of this great worldwide collection for the coming months/years through our various platforms.