Classic replacement pseudomorphs from Chessy are well known, where the malachite has replaced a previous crystal of azurite. This specimen is rather large and sharp for the location, a full size thumbnail of heft and mass bigger than the usual size we see (most are closer to 1 cm than 2 cm). The copper ore deposit of Chessy-les-Mines was mined from the Middle Ages until 1875, and after that specimens were still found by avid collectors in the dumps and old tailings, although rarely in high quality. This sharp 2 cm replacement also seems to have, unusually, a layer of chrysocolla within, and so it could be described as malachite on or after chrysocolla, after azurite. Note also, the modified shape of the crystal here is more uncommon than the typical octahedral form.