About this object

The Thompson diamond pendant and earrings are set in platinum and were designed by Harry Winston, Inc.  In 1956, Winston purchased a rough brown diamond of 264 carats from the Diamond Trading Co. of Antwerp.  In the spring of 1957, the rough was cut in to three stones weighing 36.73ct, 20.46ct and 19.12ct.  The pendant features the 36.73-ct pear-shaped fancy brown diamond and is surrounded by 33 pear-shaped colorless diamonds that total 9.03 carats.  The two smaller stones, 39.58 carats total, were set in the matching earrings accented with 72 pear-shaped colorless diamonds that total 10.75 carats.  The fancy colored diamonds are a beautiful yellowish-brown color, sometimes referred to as “cognac” color.  The National Gem Collection is noted for its colored diamonds and includes some of the world’s finest important colored diamonds on display. Diamonds, as seen here, are not necessarily colorless; in fact, very few are completely without color.  In most diamonds, a few atoms of nitrogen substituted for some of the carbon as the crystals form tint the stones yellow or brown.  Blue diamonds owe their color to boron; and red and pink diamonds, it is believed, owe their color to defects or mistakes in the crystal structure. The popularity of colored diamonds has increased dramatically in recent years, and some of the most valuable gemstones that you see in stores and at auction are fancy colored diamonds, especially in shades of blue, pink and red. Mrs. Thompson purchased the pendant and earrings from Harry Winston, Inc. in 1957 during the time that they were being produced.  The Thompson Diamonds were a bequest in 1990 and are on display in the Gem Hall at the Smithsonian’s National Museum of Natural History.