The Microcosm

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Silver Niobium Coin Series (15.)

The Microcosm - Silver Niobium Coin Series (15.)
25 Euro - Silver Niobium Coin - Special Uncirculated

• 15th Issue of the Silver Niobium Coin Series
• Unique color Technique by the Refraction of Light
• Mintage 65,000 pieces
• In original Box with Certificate of Authenticity

The German physicist Ernst Ruska demonstrated that a magnetic coil could act as an electron lens, and used several coils in a series to build the first electron microscope in 1933. The electron microscope with 12,000-fold magnification became an indispensable tool in physics, chemistry, biology and technology. The 25 Euro coin shows a raspberry-red butterfly on a grass-green niobium centre, framed by a molecular chain, an atomic symbol, and details of the butterfly. What makes the Silver Niobium coins so special is the fact that their niobium tones arise without the application of colour, purely through light refraction on an extremely thin, transparent oxide layer.