‘Perched on a slender stalk, the diamond quivered and gleamed as it slowly revolved in its specially built glass cabinet, throwing shards of coloured light across the mirrored hall. Its size and lustre drew gasps from the pressing crowds. Rarely had a single gem created such a sensation. Weighing 184 carats, the Imperial was the largest brilliant-cut diamond in the world … The stone had earned its name a few months earlier after it was shown to the Prince of Wales, who exclaimed, “What an imperial gem!” Now it was the standout attraction among £8 million worth of diamonds in the French jewellery section of the Exposition Universelle of 1889.’
THE MYSTERIOUS MR JACOB: DIAMOND MERCHANT, MAGICIAN & SPY (2017).