Lucara’s 37-Carat Bicolor Diamond Destined to Become a Landmark Pink Gem

A rare 37.41-carat rough diamond combining both pink and colorless zones has fueled the curiosity of gemologists and collectors worldwide. Unearthed at Lucara Diamond Corp.’s famed Karowe mine in Botswana, the remarkable Type IIa stone was recently analyzed by the Gemological Institute of America’s (GIA) Botswana laboratory, revealing clues about its extraordinary formation and geological history.

According to the GIA, the diamond exhibits a “mostly sharp boundary” separating its pink and white regions — a feature that suggests the two portions may have formed at different times.

Using advanced analytical techniques, including visible and near-infrared spectroscopy, GIA scientists determined that the pink coloration likely resulted from “plastic deformation,” a process in which intense geological pressure alters a diamond’s crystal structure. The colorless portion, by contrast, may have crystallized later, after the stress-causing event had subsided.

“This unique combination of color zones, size and clarity makes the diamond of great scientific and gemological significance,” said Dr. Sally Eaton-Magaña, GIA’s senior manager of diamond identification. “It may help researchers better understand how pink diamonds are formed deep within the Earth’s mantle.”

Pink diamonds are among the rarest of all natural gems, with their distinctive hue typically linked to internal lattice distortions rather than trace elements. That makes bicolor examples of this size virtually unheard of — and potentially historic once cut and polished.

HB Antwerp, Lucara’s cutting and technology partner, is now responsible for the stone’s transformation. The company’s co-founder, Oded Mansori, described the diamond as “a rare and remarkable find,” adding, “This stone has the potential to become one of the most important pink diamonds ever polished. Its intensely rich coloration is a testament to the geological uniqueness of the Karowe mine.”

The Karowe mine, located in central Botswana, has earned a global reputation for producing exceptional diamonds. Since opening in 2012, it has yielded some of the most significant stones of the 21st century, including the 1,758-carat Sewelô, the 2,488-carat Motswedi — the second-largest rough diamond ever discovered — and the 63-carat pink Boitumelo.

The discovery of this new bicolor diamond adds yet another chapter to Karowe’s legacy and strengthens the ongoing partnership between Lucara and HB Antwerp, which emphasizes traceability, transparency and value creation within Botswana’s diamond industry.

As the gem moves from rough to polished, the world’s attention will remain fixed on Antwerp — where technology and artistry will converge to unlock the full brilliance of one of nature’s most fascinating and mysterious creations.

Credits: Images courtesy of GIA. Gem photos by Tebogo Hambira, photomicrograph by Wanling Tan.