Geocronite with Fluorite

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The recent discovery of green Fluorite at Milpo mine in the Andes mountains has attracted the attention of collectors not only because of the complex cubo-octahedral forms that these crystals often take, but due to their association with sulphides that provide an unusual association in comparison to the few other green fluorite-producing places elsewhere in the world. Golden Pyrite makes for a very showy combination, but there are some extremely rare sulphosalts present too, including world-class Geocronite-Jordanite crystals. This superb miniature specimen from Milpo presents not only the rarer (for Milpo mine) cubic form of Fluorite and with a distinctly bluer-green colour, but also surrounded by large (to over 2 cm across), stepped, cyclic-twinned gun-metal grey Geocronite-Jordanite crystals. These crystals are enormous for this rare series of sulphosalts and although there is some bruising to the large crystals there are many perfect small crystals. Minor, brown microcrystals of Sphalerite are seen on the surface of the Fluorite and minor golden Pyrite and needle-like Arsenopyrite occur within the Geocronite. The Fluorite crystal is transparent, allowing the sulphides and sulphosalts underneath to be seen, like looking through a fish tank. There is slight chipping to a couple of the corners of the Fluorite cube and one corner which shows a cleavage plane, but which is intact and not repaired, but it is the colossal Geocronite-Jordanite crystals that are the eye-catcher here.