Another ‘Diamond Inside a Diamond’ Comes to Light

RAPAPORT… India Bore Diamond Holdings has found a piece of rough containing a separate diamond inside it.

The 0.84-carat outer diamond is near-colorless, while the smaller inner stone resides in a tiny cavity and can move around freely, the Australian miner said Wednesday. India Bore discovered the specimen at the Ellendale mine in West Kimberley, Australia, where it operates a portion of the site.

In 2019, Alrosa found a similar diamond with a 0.62-carat outer shell and a free-moving 0.02-carat rough inside. The Russian miner dubbed it the Matryoshka diamond, after the traditional Russian nesting dolls.

There are two main theories on how the rare diamond-within-a-diamond was formed, India Bore explained. One hypothesis is that a layer of porous diamond crystal was formed inside the outer diamond due to ultra-fast growth, but then dissolved due to high temperature and pressure, allowing a portion to be liberated and move freely inside. The second theory holds that they are possibly two separate diamond crystals, with one capturing the other during separate growth periods.

If the second assumption is true, the smaller, captured diamond would be much older than the larger outer diamond, the miner noted.

Image: The diamond inside a diamond. (India Bore Diamond Holdings)