Grandview Klein and London Jewelers trace a centennial diamond transformation

A 63-carat rough diamond took center stage at a private event during JCK Las Vegas on May 29, but the real story lies in what it is becoming: a planned 20.26-carat D-color, flawless old mine cushion intended as a centennial tribute to London Jewelers. The weight is not arbitrary. The 20.26-carat target folds the retailer’s 100-year anniversary into the stone itself, turning a gem transformation into a commemorative object with built-in meaning.

That choice of cut matters. An old mine cushion carries the visual language of another era, with a softened outline that feels distinctly antique beside today’s sharper, more modern brilliant cuts. For a house marking a century in business, the form is as eloquent as the size. The polished result is meant to read not just as a spectacular diamond, but as a statement about continuity, craftsmanship and the deliberate pace required to turn rough potential into finished rarity.

London Jewelers traces its beginning to 1926, when Charles London opened the business in a small storefront on School Street in Glen Cove, New York. The company says its earliest service model was built on house calls, with Charles London traveling to repair and wind clocks along the Gold Coast of Long Island. From that local start, the jeweler grew into a family business of fine jewelry and timepiece boutiques across Long Island and New Jersey, a trajectory that gives the centennial stone a distinctly inherited quality rather than a merely celebratory one.

The diamond will be cut in Botswana, its country of origin, under De Beers Group’s Origin by De Beers Group traceability program. De Beers describes Origin as a mine-to-market system that documents a diamond’s journey from rough to polished form through blockchain-secured traceability. The company says that as of 2025, all diamonds over one carat registered on Tracr can be traced with single-country-of-origin data, a framework that adds provenance to the stone’s already unusual narrative.

That emphasis on origin suits the collaboration between Grandview Klein Diamonds and London Jewelers, which also underscores a longstanding partnership between the Udell and Klein families. In a market where size often overshadows story, this project insists on both. The rough diamond is not only being recut into a rare polished stone; it is being turned into a record of family history, craftsmanship and place, with Botswana, Glen Cove and the centennial year all locked into one gem.