The Black Orlov
According to the legend, the Black Orlov is said to have taken its name from the Russian Princess Nadia Vyegin-Orlov who owned it for time during the mid-eighteenth century. It is a 67.50-carat cushion-cut stone, a so-called black diamond (actually, a very dark gun-metal color). It is reported to have belonged to a nineteenth-century shrine near Pondicherry, India, and to have weighed 195 carats in the rough. Unfortunately the Indian origin of this stone is almost certainly false. There is no documentation of Russia having had a princess by that name, or of India having produced any black diamonds of note.
The stone has been exhibited widely, including at the American Museum of Natural History in 1951, the Wonderful World of Fine Jewelry & Gifts at the 1964 Texas State Fair, Dallas, and the Diamond Pavilion in Johannesburg in 1967.
The Black Orlov was owned by Charles F. Winson, New York City gem dealer, who valued it at $150,000. It is mounted in a modern diamond-and-platinum necklace. An alternate name is the Eye of Brahma Diamond. In 1969, the stone was sold for $300,000. It was resold in 1990 at Sothebys for $99,000. On October 11th, 2006, the necklace containing the stone figured as lot #433 in a Christie's Magnificent Jewels sale where it sold for $352,000. Its estimate had been $100,000 to $200,000. Source: Diamonds - Famous, Notable and Unique by GIA, the Gemstone Forecaster, and the Cartier archives.