An exceedingly rare gem known as a Matryoshka diamond has been unearthed by miners in Russia.

The diamond, named for its resemblance to traditional Russian nesting dolls, was discovered in Yakutia at the Nyurba mining and processing division of Alrosa.

Experts believe it is the first known diamond in history to have this unique nested quality. They also estimate the diamond to be around 800 million years old.

Scientists studied its structure using Raman and infrared spectroscopies, as well as X-ray microtomography. Based on their studies, according to Alrosa, scientists hypothesize that the internal diamond came first and the external one formed during later stages of growth.

The rare diamond is named after Russian nesting doll toys. (Alrosa) (Alrosa)

"The most interesting thing for us was to find out how the air space between the inner and outer diamonds was formed. We have two main hypotheses. According to the first version, a mantle mineral captured a diamond during its growth, and later it was dissolved in the Earth's surface. According to the second version, a layer of porous polycrystalline diamond substance was formed inside the diamond because of ultra-fast growth, and more aggressive mantle processes subsequently dissolved it. Due to the presence of the dissolved zone, one diamond began to move freely inside another on the principle of matryoshka nesting doll," Oleg Kovalchuk, Deputy Director for innovations at Alrosa's Research and Development Geological Enterprise, said in a statement.

The Matryoshka diamond is just 0.62 carats.

An X-ray view of the rare diamond discovered by miners in Russia. (Alrosa)

"As far as we know, there were no such diamonds in the history of global diamond mining yet. This is really a unique creation of nature, especially since nature does not like emptiness. Usually, some minerals are replaced by others without cavity formation," Kovalchuk explained.

The diamond will now be sent to the Gemological Institute of America for futher testing.