The unusual “diamond in a diamond” that Russian miner Alrosa mined earlier this year, will not be put up for sale and will remain in the company’s collection of rare finds.
The collection already includes a skull-shaped rough diamond and a football-shaped rough diamond that were mined in recent years.
The latest addition to the rare-find collection resembles a traditional Russian Matryoshka doll, or a nesting doll, with one diamond moving freely inside another.
“The experts have never seen such stones in the history of diamond mining. Usually, some parts of a mineral are replaced by others without a cavity. On the other hand, regular diamonds may have small gas-liquid inclusions. However, such large cavities have never been found in crystals before,” Alrosa said.
According to scientists, the Matryoshka diamond may be more than 800-million years old.
Despite its complex structure, it weighs only 0.62 ct (0.124 g) and has a maximum size of 4.8 x 4.9 x 2.8 mm. The internal cavity volume is 6 mm3 and the internal crystal's volume is 1.6 mm3 with an estimated weight of 0.02 ct (0.004 g).
The inner diamond has a table shape and dimensions of 1.9 mm x 2.1 mm x 0.6 mm.
Scientists at Alrosa's Research and Development Geological Enterprise put forward various hypotheses on the origin of this diamond. To date, the most probable version is that both internal and external diamonds were formed at the same time.