The cutting marked an epoch. Costar and his men came over from Amsterdam for the purpose, and were installed at the Queen's jeweler's work-shop. A steam-engine was erected to do the work, and it was the Duke of Wellington himself who set the machinery in motion, and made the first cut. All England, through representatives in the press, was a breathless spectator of the thrilling scene. A single slip of the cutter's hand might have done a mischief not to be measured save by hundreds of thousands of pounds. A moment's inattention might have cost a million. Happily the operators' nerves were steady, and their thoughts concentrated on their work, so that no accident occurred. Long and loud were the controversies, to which the cutting gave rise—one party claiming that these Dutch Jews were ruining the finest jewel in England, others maintaining that without a new cutting the Koh-i-noor was comparatively valueless.
Whichever was right, Costar carried his point, and connoisseurs and the trade are now generally agreed that the cutting was beneficial. It is now a perfect brilliant, with duly proportioned table, facets, and culet. Its previous shape . . . was irregular—neither rose nor brilliant.
The stone was soon after mounted in a brooch which Queen Victoria often wore and, after her death, it was set in Queen Alexandra's crown. It was afterwards used in the crown of Queen Mary and, today, appears in the crown of Queen Elizabeth II, as seen above.