How much is a 1 lb diamond worth?

Converting pounds to carats -- gemstone weight -- means that one pound = 2,268 carats or one Troy pound = 1,866 carats. The Cullinan diamond at more than 3,000 carats is the largest raw stone found to date, and since 1906, no other notable stone approaches this weight.

The Cullinan was gifted to the King on his birthday, and remains in the possession of the British Monarchy and its crown jewels, which are priceless, since they are not for sale.