Eugénie, who also saw the great diamond at the same time, remarked that it was “simply perfection,” not knowing what to compare it with.At that time, it was the general belief that South Africa diamonds were inferior. Victoria asked, “Is it really from Cape?” Eugénie remarked, “Are you sure the diamond is from South Africa, and have you not had it polished a little? I have always been under the impression that diamonds from the Cape were very yellow and worth but little.”

The diamond was faceted into a 73-carat Old Mine cut, but eventually was sold to the London jewelry firm of Jerwood & Ward, who had it recut in Amsterdam down to a 56.60 carat Asscher cut.

It was sold to the Maharaja of Indore, a man of great wealth who abdicated in 1926 in favor of his son after a scandal had erupted over his fancy for a certain dancing girl.

In 1930 the second Duke of Westminster bought the gem, the first of a long line of collectors. It later came into the possession of an influential American family who treasured the diamond for three decades before selling the diamond to Lawrence Graff in 1987.

Graff repolished the Porter Rhodes into a 54.04 carat gem.

Sources:
Wikipedia
Famous Diamonds