From billion-dollar yachts to diamond watches and rare art, explore 15 of the most expensive things ever purchased by the ...

The Graff Hallucination was unveiled at Baselworld 2014 in Switzerland. It combines rare coloured diamonds in a variety of cuts and took thousands of hours to create this one-of-a-kind timepiece.

A rare bi-colored pink diamond of “astounding weight” was found at the Karowe diamond mine in Botswana, according to the Gemological Institute of America. Lucara Diamond A rare rough, or uncut, pink ...