It is considered to be internally and externally “flawless” – placing it among the world’s most chemically pure, transparent ... most expensive remains a rectangular 163.41-carat diamond ...

A pink diamond closed at auction for $57.73 million in Hong Kong Friday night, the most expensive diamond per carat ever sold. The 11.15-carat Williamson Pink Star diamond sold at a Sotheby’s ...

Most Expensive Diamond: As the world’s most expensive diamond ever sold at auction, Pink Star has certainly made a name for itself. It has unmatched colour, clarity, size, and cut. Read further ...

An exceptionally rare blue gem became one of the most expensive diamonds sold by Christie’s when it went under the hammer in Geneva on Tuesday. An unidentified buyer paid CHF 39,505 million ...

That 11.15-carat diamond holds the title for the most expensive diamond per carat ever sold – $5.2 million per carat. However, its presale estimate was $1.9 million per carat, Barron's reported.

NEW YORK -- The world's most expensive diamond and ruby have been sold in the same auction -- a first in auction history. A 55-carat ruby sold for nearly $35 million at Sotheby's Magnificent ...