March 26, 2025

Uncle Sam Diamond, Subway Chain Owe World of Gratitude to Dr. Peter Buck

What do the Uncle Sam Diamond and the Subway sandwich chain have in common? They both owe a world of gratitude to Dr. Peter Buck.

In June of 2022, the Smithsonian’s National Museum of Natural History unveiled the “Great American Diamonds” exhibit, highlighting four of the most stunning diamonds ever found in the United States. The headliner of the group was the Uncle Sam Diamond, a 12.4-carat emerald-cut stone fashioned from the largest uncut American diamond ever discovered.

The way the Smithsonian obtained the stone was through the generosity of Buck, who was not only a longstanding member of the Smithsonian National Museum of Natural History’s Advisory Board, but also the co-founder of 37,000-store Subway chain.

Dr. Jeffrey Post in his book, Unearthed, emphasized how Buck pounced on the opportunity to acquire the Uncle Sam Diamond after it has been out of the public eye for more than 50 years.

“He immediately decided that the Uncle Sam Diamond was a national treasure that should be available for all to see,” he wrote, “and he purchased it for the Smithsonian National Gem Collection in 2019.”

A nuclear physicist by trade, Buck is famous for making one of the most brilliant investments in US history. In 1965, at the age of 35, Buck loaned $1,000 to his family friend, Fred DeLuca, so he could open a sandwich shop. That shop was intended to help the 18-year-old DeLuca pay for college at the University of Bridgeport in Connecticut. DeLuca honored his benefactor by naming the shop “Pete’s Super Submarines.” That single store has since grown into the Subway sandwich chain, with worldwide sales reaching nearly $10 billion.

The near-flawless 12.4-carat pinkish-brown Uncle Sam Diamond was cut from a crystal weighing a whopping 40.23 carats. The rough gem was discovered in 1924 at the Prairie Creek mine (now known as Crater of Diamonds State Park), making it the largest faceted diamond ever discovered in the Arkansas mine.

The Uncle Sam Diamond embarked on a 98-year winding path until it finally settled into its display at the Janet Annenberg Hooker Hall of Geology, Gems and Minerals at the National Museum of National History in Washington, DC.

According to Post, the retired Curator of the National Gem and Mineral Collection at the Smithsonian Institute, the Uncle Sam Diamond in its original rough form was acquired from Arkansas Diamond Company shareholder Tomas Cochran by Schenck & Van Haelen of New York, a cutter that specialized in Arkansas diamonds.

Ernest G.H. Schenck cut the 40-plus-carat rough gem into a 14.34-carat parallelogram, and then recut it into a more traditional 12.42-carat emerald-cut gem to improve its overall brilliance. Boston jeweler Sydney DeYoung bought the stone from Schenck’s estate in 1955 and then sold it about five years later to B. Beryl Peikin of Peikin Jewelers of Fifth Avenue, NY.

When Peikin passed away in 1988, the famous diamond (now set in a ring with two smaller Arkansas-sourced diamonds) remained in the possession of his wife until she passed at the age of 102. Jeweler DeYoung became the next owner, just briefly, until Buck proposed to take the gem to Washington for all to see.

Although he purchased the Uncle Sam Diamond in 2019, he would never get to see the “Great American Diamonds” exhibit. He passed away in November 2021, just five months ahead of the exhibit’s unveiling.

Credit: Photo by James D. Tiller / Smithsonian.