Diamond Jubilee celebrated with creation of world’s smallest diamond coin

Scientists at the University of Glasgow have created an unusual tribute to Her Majesty the Queen to mark her Diamond Jubilee - the world's smallest commemorative coin, made from a tiny sliver of diamond. The 'coin', created at the University's James Watt Nanofabrication Centre, measures just 750 nanometres across and features an image of the Queen's profile just 580 nanometres high. A nanometre is one billionth of a metre. Around 1300 of the diamond coins could fit side by side on the width of the smallest letter on a five pence piece, and 2,600 billion of the coins would fill a volume equivalent to that of a pound coin. The image was etched on a laboratory-grown diamond covered in a special polymer. Using high-resolution electron beam lithography, the profile of the Queen's head was patterned onto the polymer. The pattern was then transferred to the diamond using a process known as ICP reactive ion etching.