An incredible discovery in Siberia by the Russian mining company Alrosa: A diamond found trapped inside another diamond. Presumably the first discovery of its kind.

This diamond is nicknamed Matryoshka, like the Russian dolls.

The outer diamond is only 0.62 carat (4.9 x 4.8 x 2.8 mm) and the second is enclosed in a cavity where it can move freely. The tiny nested crystal has an estimated weight of 0.02 carats (2.1 x 1.9 x 0.6 mm).

The X-ray view (Photo below) shows a cross-section of the diamond.

Scientists hypothesized that the internal diamond formed first and was later enclosed by a larger crystal during the formation process.

"To our knowledge, there are no such diamonds in the history of diamond mining. It's truly a unique creation of nature, especially since nature doesn't like emptiness," said Oleg Kovalchuk of Alrosa.  

I'd be curious to know the value of the Matriochka diamond. No indication has been given whether it will be put on the market.

For a designer, such a diamond would be a challenge to put it in majesty in a piece of jewelry. This diamond will remain raw, because a cut is impossible without breaking the outer diamond because of the cavity inside.

(Photos: X-ray of the Matryoshka Diamond (Copyright Alrosa PJSC))