Admiral Lord Nelson's diamond Chelengk is one of the most famous and iconic jewels in British history. Presented to Nelson by the Sultan Selim III of Turkey after the Battle of the Nile in 1798, the jewel had thirteen diamond rays to represent the French ships captured or destroyed at the action. A central diamond star on the jewel was powered by clockwork to rotate in wear. Nelson wore the Chelengk on his hat like a turban jewel, sparking a fashion...