Last updated on April 10, 2023
The Logan Sapphire is one of the world’s most recognizable gemstones. On display at the National Museum of Natural History since 1971, it is the largest gemstone in the National Gem Collection and one of the largest faceted blue sapphires in the world.
Origin of the Logan Sapphire
The early history of the Logan Sapphire is unknown except that it originated in Sri Lanka, likely Ratnapura, known as the “City of Gems”. It is assumed that the crystal was mined in the 19th century; however, no records confirming this are available.
The history of the gem trade in Sri Lanka dates back more than two millennia, and no gemstones in the rough state were exported out of the country, even in ancient times. That means that the sapphire was also originally cut by local lapidaries, presumably the Moors of Sri Lanka, who were well-versed in the technique of gem cutting from ancient times.
The Sri Lankan cutters of the time always tried to maximize gemstone weight at the expense of cut quality and light performance, which is why exported gemstones were usually recut in the cutting centres of Europe. However, it is unknown whether the Logan Sapphire was recut in Europe after getting exported from Sri Lanka. In any case, the lapidarist of the gem created a large table to reveal the flawless interior of the stone and the rich blue colour.
History of the Logan Sapphire
Rumour has it that the first owner of the Logan Sapphire was a native of Sri Lanka, beheaded for hiding his discovery from his leader. One of the gemstone’s early owners was Sir Ellice Victor Sassoon, 3rd Baronet of Bombay, a businessman and hotelier from the wealthy Sassoon family. Supposedly the Sassoon family may have acquired the sapphire from a maharaja in India.
The sapphire was exhibited at the 1939 New York World’s Fair held at Flushing Meadows-Corona Park in Queens, New York, United States. Sassoon planned to auction the gem in 1941 to raise money for the British war effort during World War II (September 1, 1939 – September 2, 1945), but the auction did not take place.
In the early 1950s, Sassoon sold the gem to the American diplomat Meyer Robert Guggenheim who gave it to his wife, Rebecca Pollard Guggenheim, as a Christmas and anniversary gift in 1952. Mrs Guggenheim often wore the sapphire on a clip at formal events, but it was so heavy that she had to wear it with a shoulder strap.
In December 1960, a year after her husband’s death, Mrs Guggenheim deeded four-sevenths of the gem to the Smithsonian Institution and the remaining portion the following year. The transaction was only in deed, and the sapphire was not physically divided. She wanted the gem to be reserved and worn only by the First Lady of the United States on appropriate occasions, which never happened.
In 1962, after marrying John A. Logan, a management consultant, Rebecca Guggenheim changed her surname to Logan, and one of the world’s largest sapphires became known as the Logan Sapphire.
The Logan Sapphire was transferred to the Smithsonian Institution in April 1971. Since then, the gemstone has been on display in the National Gem Collection of the National Museum of Natural History in Washington, D.C.
Logan Sapphire Characteristics
The Logan Sapphire, one of the world’s largest faceted blue sapphires, weighs 422.98 carats or 84.596 grams. It is approximately the size of a large chicken egg and measures 49.23 mm × 38.26 mm × 20.56 mm. The colour is described as blue with slight shades of violet.
The Logan Sapphire features a rectangular shape and a mixed cushion cut, designed to highlight its rich colour rather than maximize its brilliance. A Gemological Institute of America (GIA) report dated June 1997 states that the Logan Sapphire’s colour is natural, with no evidence of heat treatment detected. Under longwave ultraviolet radiation, it fluoresces a moderate reddish-orange, which indicates trace amounts of chromium in the sapphire’s structure.
The Logan Sapphire is set in a silver and gold brooch featuring 20 round brilliant cut diamonds, totalling approximately 16 carats. According to a 1959 article in Ladies’ Home Journal by Rebecca Pollard Guggenheim, the sapphire was set in the brooch sometime after she had acquired it several years earlier. However, details of the setting and origin of the diamonds are unknown.
Featured image: Chip Clark, Smithsonian staff / Wikimedia Commons