Rare!!! - Fine pair of black Pyritized Ammonite halves - hand-polished - Speetoniceras sp. - 340×310×90 mm

Very rare Ammonite Speetoniceras. The specimen stands out not only for its remarkable size, 34 cm of diameter, but especially for the beauty of its fossilisation. Pyritisation of animal tissues requires the presence of several concurrent conditions, like the initial process of decomposition by anaerobic bacteria that produces a quantity of sulphur, whose subsequent reaction with ferrous materials starts the process of oxidation to reach the final pyritisation of the soft parts of the body. The beauty of this dissected ammonite is also in the exceptional and extremely elegant combination between the gold colour of the pyrite and the black background, rarer than the brown tones to which we are more commonly used to. A beautiful decorative piece that will give lustre and perfectly adorn any space. Fun fact: in one of the 2 slices, you can find the inclusion of a small Orthoceras. Dimensions of the single slice: approx. 340 x 310 x 45 mm. Weight: 10400 g.