Britain's Crown Jewels include a "super deep" diamond that was formed close to the Earth's core. The Cullinan Diamond is the largest diamond ever discovered and experts have used pioneering laser technology to establish its origins.

 

 

It is one of two originating more than three times deeper than most diamonds in the Earth's mantle, before eventually being thrust up through volcanic eruptions, according to the Daily Mirror.

 

 

It was discovered in a mine in South Africa in 1905 and now forms centerpiece of the Crown Jewels. It was presented as a symbolic gesture intended to heal the rift between Britain and South Africa following the Boer War.

 

 

The second diamond found to have such traces of bridgmanite was the Hope diamond discovered in India and kept at the Smithsonian Institute in the United States.

 

 

Dr. Wuyi Wang, of the Gemological Institute of America, said: "Discovering the deep mantle origin means that the material in these diamonds undergoes a remarkable journey."

 

 

The majority of diamonds form in the base of the continental tectonic plates at around 150-200km deep but some rare diamonds formed deeper in the mantle.

 

 

The New York-based team identified remnants of a mineral called bridgmanite in the Cullinan which is blue-white in color.

 

 

The Cullinan Diamond weighed 3,107 carats in its uncut form and now consists of nine large stones and 96 smaller stones.

 

 

The two largest stones were set in to the Sovereign's Scepter and Imperial State Crown.