Logan sapphire
Encyclopedia
The Logan sapphire is a flawless specimen from Sri Lanka
, a cushion-cut stone which possesses a rich deep blue color and is the second largest (blue) sapphire
known, weighing 422.99 carats (84.6 g).
The Logan sapphire is named after Mrs. John Logan, who donated the gemstone to the Smithsonian Institution
in 1960.
The cushion-cut stone is one of the world's most famous and largest sapphires and is set in a brooch surrounded by 20 round brilliant cut diamond
s weighing in total 16 carats (3.2 g). It is currently on display at the National Museum of Natural History
in Washington, D.C.
, alongside the Bismarck Sapphire Necklace
and the Hall Sapphire and Diamond Necklace
.
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, a cushion-cut stone which possesses a rich deep blue color and is the second largest (blue) sapphire
Sapphire
Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...
known, weighing 422.99 carats (84.6 g).
The Logan sapphire is named after Mrs. John Logan, who donated the gemstone to the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
in 1960.
The cushion-cut stone is one of the world's most famous and largest sapphires and is set in a brooch surrounded by 20 round brilliant cut diamond
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
s weighing in total 16 carats (3.2 g). It is currently on display at the National Museum of Natural History
National Museum of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. Admission is free and the museum is open 364 days a year....
in Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
, alongside the Bismarck Sapphire Necklace
Bismarck Sapphire Necklace
The Bismarck Sapphire Necklace is a sapphire necklace designed by Cartier, Inc. in 1935. As of 2010, the necklace is on display between the Hall Sapphire and Diamond Necklace and the Logan Sapphire in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals at the Smithsonian Institution's...
and the Hall Sapphire and Diamond Necklace
Hall Sapphire and Diamond Necklace
The Hall Sapphire and Diamond Necklace has 36 matched sapphires from Sri Lanka which total 195 carats. These sapphires are surrounded by 435 pear-shaped and round brilliant-cut diamonds that total 83.75 carats. The setting is platinum....
.