Diamond

A superb, actually shocking, twinned diamond crystal weighing 17.8 carats. Such large well-formed crystals are almost nonexistent, for several reasons. In Nature, they rarely form and survive to begin with; but the greater threat is from the miners and mining companies that necessarily cut these few rare large crystals into stones for the public consumption! Crystals like this only come to market in large parcels sold as rough material for cutting, to Sightholders (wholesale diamond merchants). This came through one such source in NYC's diamond district, and was saved by a mineral collector/dealer for a personal collection of gem crystals. It is thought to have come out in the mid-2010s. This crystal is exquisitely twinned as a "macle twin" which gives it the unique triangular, but natural, geometry. Perhaps the best such diamond crystals of this twinned habit that a collector could ever wish to own. As of 2026, this De Beers property is the largest diamond mine in South Africa.