Beautiful play of red, green and rare blue colours in this Opalised Fossil Belemnite from the Coober Pedy Opal field in Australia. The specimen measures to 5.1cm long with a diameter of up to 1cm. A rare and beautiful Opalised Belemnite from Coober Pedy. (The opal at Coober Pedy is hosted in the Cretaceous Bulldog Shale (Marree Subgroup), while deposition of the Opal is believed to be Late Oligocene or Early to mid-Miocene).