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Logan Sapphire - Smithsonian Museum of Natural History - 2012-05-17 | by Tim Evanson
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Logan Sapphire - Smithsonian Museum of Natural History - 2012-05-17

The Logan Sapphire, a cabochon-cut sapphire, on display in the Hall of Gems and Minerals at the Smithsonian Museum of Natural History in Washington, D.C.


Sapphires are gemstones that are made of the mineral corundum (crystalline aluminum oxide). Pure corundum is colorless, but when trace elements like chromium, vanadium, iron, or nickel get mixed in it takes on color. The red variety is known as ruby; all the other varities are known as sapphires. The violet-blue color is caused by the presence of titanium, iron, and vanadium.


The Logan Sapphire was mined in Sri Lanka, probably in the 19th century. It was also undoutedly cut there. It is a table-cut sapphire. This means that it was cut to look like a four-sided diamond. A little less than half of the top point was then cut off, to allow better viewing of the interior. It is not clear if the sapphire was point-cut in Sri Lanka and recut in Europe, or if it was table-cut in Sri Lanka. At the time, most sapphires were exported to Paris or London and then sold there. That is probably where it was first sold.


The provenance of the gemstone is not clear. At some point, it was purchased by the Guggenheim family. Meyer Guggenheim was a Swiss Jew who emigrated to the United States in 1847. He became one of the wealthiest men of the 19th century by engaging in mining and smelting. In 1901, he purchased the American Smelting and Refining Company (ASARCO) from William Rockefeller. His second eldest son, Daniel, helped run ASARCO. His fourth son, Solomon Guggenheim, helped spark the Alaska gold rush in the early 1900s -- and made the family even more wealthy.


Rebecca "Polly" Pollard was a divorcé who married Meyer Robert Guggenheim (son of Daniel) in 1938. Guggenheim was a colonel in the U.S. Army, and Ambassador to Portugal from 1953 to 1954. During their marriage, the Guggenheims were one of D.C.'s most prominent families. In 1958, the Guggenheims helped to found the Frank Guggenheim Hall of Gems and Minerals at the Smithsonian Institution. Robert Guggenheim died in 1959. "Polly" Guggenheim then married John A. Logan, a management consultant, in 1962. He died in 1982, and she died in 1994.

Robert Guggenheim gave his wife the sapphire in 1952. It undoutedly had acquired its setting by then.


The year after Robert Guggenheim's death, Polly donated the Logan Sapphire to the Smithsonian. However, she retained the sapphire in her possesion until 1971. By then she was Mrs. John A. Logan, and the sapphire was called the Logan Sapphire. It went on display in June 1971.


The Logan Sapphire is set in a silver and gold brooch setting. Twenty round brilliant-cut diamonds weighing approximately 16 carats are set around the edge of the brooch. The Logan Sapphire is unusually blue and very unusually clear for a stone of its size. There was some concern that the sapphire might have been treated with heat or radiation at some point to bring out this color. But it was examined by the Gemological Institute of America in 1997 and found to be completely natural.

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Taken on May 17, 2012