Microcosm Butterfly Niobium Bimetallic 25 Euro Silver Coin
Austrian Mint released the 25 euro silver niobium bimetallic coin called Microcosm, and it is a part of the famous “Niobium” series, dedicated to the world’s science and technological innovations. The Microcosm coin is struck from 9 g silver 900 combined with niobium, which makes the total weight 16.5 g. The coin is 34 mm in diameter. Ninety percent of the outer ring is pure silver while the centre disc is composed of primarily niobium, a soft, ductile metal when pure that is hardened by impurities. The coin housed in a special case and shipped with a numbered Certificate of Authority from the Austrian Mint in a protective slipcase. The coin having a limited mintage to 65.000 pieces worldwide.
The obverse features the “raspberry-red” butterfly set against a “grass green” field on the niobium inner disc. The colors are produced via a special oxidation process. Inside the inner disc, above and between, the butterfly’s antennae, shows an atomic model created by Danish physicist Niels Bohr. the nucleus is red and three revolving electrons, identical to the butterfly, while the orbits are lighter green. The butterfly’s left wing partially hides a molecular model that crosses over from the left of the outer ring. The year 2017 is inscribed beneath the butterfly. On the reverse the central disc shows a close-up of the surface of pollen. Within one of the cells is a realistic portrayal of a female bee. To the right of the bee is a 3D model of a chemical compound that resembles that of methane (CH4). Below the bee is a pollen grain.