The DeYoung Pink Diamond was discovered at the Williamson mine in Tanzania, a site globally renowned for producing some of the world’s most extraordinary coloured diamonds—especially pink ones.
After its discovery, the stone made its way into the international diamond market during the late 1950s. It was part of a lot of rough pink and blue diamonds purchased by the Baumgold Brothers, a leading U.S. diamond-cutting firm, from De Beers, the dominant force in the global diamond trade at the time.
The Baumgold Brothers later partnered with the J. & S.S. DeYoung jewellery firm in Boston to market and sell the cut gems. One standout among them was a 2.82-carat diamond that, once faceted into its striking pear shape, revealed an intense purplish-pink hue with remarkable brilliance.
This gemstone became part of Sidney DeYoung’s private collection, a prized possession held for several years. Recognising its scientific and aesthetic significance, DeYoung donated the diamond to the Smithsonian Institution in December 1962, where it remains a highlight of their gem collection today.