“Acanthite crystals covering native silver on calcite matrix with late light brown calcite crystals. The acanthite is a recent growth that forms within hours of opening the vugs containing the native silver. Usually the formation of acanthite is complete within three weeks when the specimen reaches a stable state. Sealing the specimen in an air-tight container immediately after opening the vug does not protect the specimen but it slows the deposition of acanthite that it takes up to six months to reach a stable state. Cleaning the native silver from the acanthite only results in its re-deposition. It is interesting to observe that some parts of the native silver seem to be immune to the superficial development of acanthite with areas remaining bright and shiny over a long period of time becoming only slightly tarnished over time. It is possible (although not having been checked on the few specimens that are available) that the chemical composition of the silver varies slightly leading to this phenomenon. The specimen depicted is a Christmas present from my dear friend Fritz Schreiber who self-collected it. Camera: Nikon D7000 mounted on a WILD M420 Macroscope Stacking: composed of 110 pictures with Zerene Stacker, Pyramid algorithm”

“Miargyrite pseudomorphs after pyragyrite, wires of native silver growing out of these pseudomorphs and acanthite crystals covering native silver on calcite matrix with late brown calcite crystals. ID of Miargyrite established by PXRD, ID of acanthite established by SXRD. The acanthite is a recent growth that forms within hours of opening the vugs containing the native silver. Usually the formation of acanthite is complete within three weeks when the specimen reaches a stable state. Sealing the specimen in an air-tight container immediately after opening the vug does not protect the specimen but it slows the deposition of acanthite that it takes up to six months to reach a stable state. Cleaning the native silver from the acanthite only results in its re-deposition. It is interesting to observe that some parts of the native silver seem to be immune to the superficial development of acanthite with areas remaining bright and shiny over a long period of time becoming only slightly tarnished over time. It is possible (although not having been checked on the few specimens that are available) that the chemical composition of the silver varies slightly leading to this phenomenon. The specimen depicted is a Christmas present from my dear friend Fritz Schreiber who self-collected it. Camera: Nikon D7000 mounted on a WILD M420 Macroscope Stacking: composed of 100 pictures with Zerene Stacker, Pyramid algorithm FOV: 10 mm ”

“Wires of native silver growing out of Miargyrite pseudomorphs after pyragyrite and acanthite crystals covering native silver on calcite matrix with late calcite crystals. ID of Miargyrite established by powder diffraction, ID of acanthite established by SC analysis. The acanthite is a recent growth that forms within hours of opening the vugs containing the native silver. Usually the formation of acanthite is complete within three weeks when the specimen reaches a stable state. Sealing the specimen in an air-tight container immediately after opening the vug does not protect the specimen but it slows the deposition of acanthite that it takes up to six months to reach a stable state. Cleaning the native silver from the acanthite only results in its re-deposition. It is interesting to observe that some parts of the native silver seem to be immune to the superficial development of acanthite with areas remaining bright and shiny over a long period of time becoming only slightly tarnished over time. It is possible (although not having been checked on the few specimens that are available) that the chemical composition of the silver varies slightly leading to this phenomenon. The specimen depicted is a Christmas present from my dear friend Fritz Schreiber who self-collected it. Camera: Nikon D7000 mounted on a WILD M420 Macroscope Stacking: composed of 132 pictures with Zerene Stacker, Pyramid algorithm FOV: 9 mm”