Ultra rare Australian «diamond within a diamond» to be studied

IBDH has released details of a rare «double diamond» recovered from its Ellendale alluvial deposit in Western Australia.
The near-colourless 0.844 carat diamond is one of a very rare group of diamonds dubbed «Matryoshka» diamonds after the popular Russian nesting dolls. The smaller diamond is contained within in a cavity inside the larger diamond and can roll about freely inside, ibdh.com.au reports.
The diamonds both exhibit a rare purple hue under ultraviolet light.
Thought to have formed up to 1400 million years ago and some 200 kms below the surface of the earth the stone has been brought to the surface by volcanic activity. 
There are two main theories on how the unusual diamond crystal combination was formed. 
One theory is that a layer of porous diamond crystal was formed inside the diamond due to ultra-fast growth, but then high temperatures and pressures subsequently dissolved the porous layer allowing a smaller and harder core to be liberated and move freely inside the harder outer.
Moreover the smaller captured diamond could be millions of years older than the larger outer diamond. 
In any case, this «double diamond» is a remarkable creation of nature, made even rarer by its purple glow under UV light. Such ultra rare and unusual diamond specimens are highly sought after by collectors world wide.

Alex Shishlo for Rough&Polished