London Jewelers and Grandview Klein unveil 63-carat rough diamond to mark Centennial

To celebrate its 100th anniversary, London Jewelers partnered with Grandview Klein Diamonds to transform a 63-carat natural rough diamond into a one-of-a-kind 20.26-carat D Flawless Old Mine Cushion-cut diamond. The project was unveiled during an event at JCK Las Vegas on May 29. Speakers included Mark and Candy Udell, owners of London Jewelers; Moshe Klein, chief executive officer of Grandview Klein Diamonds; Al Cook, chief executive officer of De Beers Group; and Don Gaetsaloe, permanent secretary of Botswana’s Ministry of Minerals and Energy.

The finished diamond’s planned weight of 20.26 carats was chosen to commemorate London Jewelers’ centennial year. The rough diamond will be cut in Botswana, its country of origin, through De Beers Group’s ORIGIN program, which tracks a natural diamond’s journey from rough to polished stone through verified provenance. The cutting process will be documented from start to finish, providing insight into the craftsmanship and technical expertise involved in producing a diamond of this size and quality.

Once completed, the diamond is expected to rank among the rarest natural diamonds in the world, according to London Jewelers and Grandview Klein. A D Flawless grade represents the highest standard of diamond quality, indicating a colorless stone with no internal imperfections visible under 10x magnification. “For 100 years, London Jewelers has been built on craftsmanship, resilience, family and relationships that span generations,” said Mark Udell. “This extraordinary diamond represents our history, our family and the future still ahead of us.”

The finished gem will be fashioned in the Old Mine Cushion style, one of the earliest diamond cuts. Known for its rounded outline and distinctive faceting, the cut originated centuries before modern diamond-cutting technology. “We are cutting a new diamond in an old style because we honor our past, but we are shaping the future,” said Scott Udell.