Returning for the third time since its mining in 1901, the 'Red Cross', a fancy intense yellow, cushion-shaped 205.07 carat diamond and a 228.31 carat white diamond called 'The Rock' that could fetch 30 million US dollars and is the largest ever seen throughout auction market history, are pictured during a preview at Christie's before their auction sale in Geneva, Switzerland, May 6, 2022. REUTERS/Denis Balibouse