‘Beating Heart’ Demonstrates Ultra-Rare Diamond-in-a-Diamond Phenomenon

The De Beers Institute of Diamonds just revealed "Beating Heart," a fascinating and ultra-rare diamond-in-a-diamond. Weighing about 1/3 of a carat, the unusual rough stone has an internal cavity with a free-moving, smaller diamond trapped inside.

De Beers Group unearthed the Beating Heart at one of its four global mining locations (Botswana, Canada, Namibia or South Africa) although it's still not clear which one delivered this treasure. Sorters at De Beers Group Sightholder VD Global (VDG) in India identified the unusual stone as a "significant anomaly" in October 2022 and sent it back to the UK for analysis.

An arsenal of sophisticated equipment developed by De Beers Group Ignite, including the DiamondView and SYNTHdetect, was used in a preliminary analysis of the diamond, followed by optical and scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and fluorescence and phosphorescence imaging.

Armed with this information, the De Beers Institute of Diamonds (IoD) was able to provide an explanation of how the 0.329 carat, D-color, Type IaAB diamond came to be.

Scholars at the institute believe that the diamond's formation process occurred in three phases. The inner "core" consisted of good-quality diamond growth, followed by a middle layer of growth that was poor and fibrous. The final, outer layer, was a coating of gem-quality crystal.

At some point between its formation and travel to the surface of the Earth, the poor-quality middle layer etched away, leaving only the untethered core and the outer coating.

"The Beating Heart is a remarkable example of what can happen on the natural diamond journey from formation to discovery," noted Jamie Clark, head of global operations at IoD. "We would like to thank VD Global for recognizing this diamond's potential and acknowledging its educational and scientific potential."

While the Beating Heart is a true oddity, it's not the first of its ilk.

Back in 2019, mining company Alrosa surprised its Instagram followers with a video that seemed to show a tiny rough diamond rattling around in the cavity of a larger one. The caption read, “A diamond in a diamond? We couldn’t help but share this very special find with you.”

Alrosa researchers utilized Raman spectroscopy, infrared spectroscopy and X-ray microtomography to confirm that both the smaller crystal and its host were diamonds.

Alrosa named the curious double-diamond “Matryoshka” — a nod to the popular Russian nesting dolls. The diamond was discovered in Yakutia at the Nyurba mining and processing division of Alrosa.

Still another diamond-in-a-diamond was unearthed by India Bore Diamond Holdings (IBDH) in 2021 at its Ellendale alluvial deposit in Western Australia. The mining company reported finding an 0.844-carat flat, triangular gem, which contained a second diamond weighing just 0.001 carats.

IoD noted that the Beating Heart specimen will be left intact so it can be used for research and educational purposes with the consent of VDG.

Alrosa also had clarified in 2019 that the Matryoshka diamond had been added to its collection of rare finds — and was not for sale.

Credits: Electron microscope image by Ivan Nikiforov / De Beers Institute of Diamonds. "Beating Heart" diamond photo by Danny Bowler / De Beers Institute of Diamonds. "Matryoshka" diamond courtesy of Alrosa.