Updated February 26, 2026 at 4:01 PM EST
To mark the 250th anniversary of the United States, we’re cataloging 25 objects that define the country’s history.
The United States does not have a rich diamond mining history, but an exhibit at the Smithsonian Institution’s National Museum of Natural History proves that some of the world’s most dazzling gems are homegrown.
Here & Now’s Scott Tong speaks with Gabriela Farfan, the Smithsonian’s Coralyn Whitney Curator of Gems and Minerals, about what makes the Uncle Sam Diamond and the Freedom Diamond so special.
5 questions with Gabriela Farfan
What’s the story of the Uncle Sam Diamond?
“Just over 100 years ago, in July of 1924, the Uncle Sam Diamond was discovered by Mr. Wesley Oley Basham, who was a miner at the Arkansas Diamond Corporation. And it was a whopping 40.23 carats. That’s a pretty large diamond if you think about your average engagement ring. This is indeed the largest diamond ever found in the United States, including all the diamonds that have been found since.
“But every time you take a crystal, an artisan or a gem cutter has to essentially polish all of its facets and turn it into a gem that you would wear in a piece of jewelry. It gets them a lot smaller. And so the Uncle Sam diamond was actually cut twice. The first time, it was cut into a 14.34- carat parallelogram, which is a bit of a wonky shape, and so it was later recut into a more elegant, elongated emerald cut. And this type of cut is ideal for showcasing just how flawless this particular diamond is.”
Can you say more about this source location?
“The Crater of Diamonds is a very famous mine in Arkansas. It’s one of only two diamond mines in the United States that have produced commercial diamonds. And you can actually dig there today. It’s a state park run by Arkansas, and you can actually dig for diamonds yourself.”
What’s the story of the Freedom Diamond?
“Gigantic, more than 16 carats, as I understand it, not found until the 1990s.
“The Freedom Diamond is currently the largest faceted or cut diamond from the United States. It’s from the Kelsey Lake Diamond Mine in Colorado, which is the second commercial diamond mine.
“And this diamond is also very beautiful. It has a slight undertone of yellow, and it’s actually set into a ring flanked by two other diamonds. And this stone completely covers the width of my ring finger when I put it on. It probably extends beyond the width of my ring finger. So it’s a very large stone. It would make a statement.”
Why weren’t diamond mines commercially viable in the U.S.?
“Mining is very difficult work, and unlike the gold rush, where it was kind of free for all, and everyone could come, these were commercially run mines. And it’s much more difficult to source diamonds out of kimberlite or lamberlite, which are the rocks that these diamonds are in. This versus going through a bed and finding gold.”
How did these diamonds come into the hands of the Smithsonian?
“One of the wonderful things about the National Gem Collection is that it is built entirely by donations. And so the Uncle Sam Diamond was gifted to the collection in 2019, and about one month later, a couple decided to gift the Freedom Diamond. So suddenly, this meant that we had two of the most important American diamonds in the National Gem Collection, which clearly warranted a new exhibit for these great American diamonds. And so we decided to put them on exhibit and pair them with two crystals from their respective mines.
“Giving something to the Smithsonian is a truly special act because it means that it belongs to everyone. And so, especially with these American treasures, I think people see value in having these belong to the American public and to the world.”
This interview was edited for clarity.
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Will Walkey produced and edited this interview for broadcast with Catherine Welch. Walkey also produced it for the web.
This article was originally published on WBUR.org.
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