(IDEX Online) - Miners in Australia have unearthed the world's second ever Matryoshka or Russian doll diamond. The 0.844-carat flat, triangular gem has a cavity that contains another tiny diamond, reckoned to be just 0.001-ct, which can freely roll around inside.It was discovered by India Bore Diamond Holdings (IBDH) in the southern part of the Ellendale alluvial deposit, in Western Australia.The gem (pictured), which also boasts a rare, purple fluorescence, is largely than the world's first Matryoshka, discovered by Alrosa in October 2019 during sorting at at its Nyurba division, in the Russian republic of Yakutia. The host crystal weighs 0.62-cts and the detached gem inside the cavity is 0.03 carats.Patrick Stringer, director at Australian miner IBDH, said: "The stone was not recognized at the mine as anything extra-special and it was only at the sorting room and later at the lab that the true rarity of the stone was recognized by our specialists. They couldn't really believe it when they first saw it!"