A remarkable 37.41-carat rough diamond, cleanly divided into one pink half and one colorless half, has been unearthed at Botswana’s Karowe mine and examined in Gaborone.

The study was led by Dr. Sally Eaton-Magaña of the Gemological Institute of America (GIA), whose research specializes in diamond color and identification. GIA reported a strikingly sharp boundary between the two zones, noting the stone’s dimensions as approximately 1 × 0.63 × 0.57 inches.

Experts believe the diamond formed in two separate geological phases. Similar two-tone diamonds examined in the past rarely exceeded two carats, making this find extraordinary. Researchers suggest the pink section was originally colorless but transformed under intense stress, while the colorless portion likely formed later. The diamond is categorized as type IIa, known for extremely low nitrogen levels, which enhances the vivid contrast.

How Pink Diamonds Form

Unlike most colored diamonds that owe their hues to impurities or radiation, pink diamonds get their color from lattice distortion; shifts in the internal atomic structure affecting how the crystal absorbs light. Too much distortion turns the stone brown; too little leaves it colorless. In many diamonds, the pink color forms in thin bands called lamellae that reflect ancient slip planes within the crystal.

Diamond Formation Deep in the Earth

Diamonds originate over 100 miles below the surface in the mantle and travel upward rapidly through kimberlite eruptions, which prevents them from altering into graphite. Their purity means any color present typically comes from structural defects or stress, making this two-tone crystal a rare geological timeline preserved in a single stone.

Some diamonds form even deeper in the mantle’s transition zone, carrying microscopic inclusions that provide clues to early Earth processes.

Karowe Mine’s Legacy of Exceptional Finds

Karowe, known for its stable ancient crust, continues to yield unusual rough stones. In 2024, it produced the 2,488-carat Motswedi. This new half-pink, half-colorless rough adds to the mine’s reputation for extraordinary discoveries. Modern recovery systems help ensure large crystals survive the mining process intact for scientific study.

A Window Into Ancient Supercontinents

Research suggests that major shifts during the breakup of Earth’s early supercontinent Nuna played a role in creating pink diamonds by deforming the crust and altering deep mantle pathways. This two-stage pink-and-colorless stone aligns with that theory, offering a rare natural record of changing geological conditions.

Why This Diamond Matters

The crystal presents a built-in “before and after” within the same specimen, allowing scientists to compare the pink and colorless sections directly. That makes it invaluable for studying the physics of defect centers and the processes that create rare diamond colors.

Cutting the stone will require careful planning: preserve the boundary for science or maximize pink yield? Before any decision, nondestructive testing will map internal features to protect this exceptional geological archive.

Conclusion

For gem enthusiasts, this news is more than a luxury headline. It’s an exciting reminder of how rare and historic gemstones continue to influence the modern jewelry world. Many would be curious about the stone’s origin, craftsmanship, cut, and what makes it worthy of such a high-profile purchase. For students, it’s a real-world example of how iconic gems shape trends, collector interest, and future jewelry design.