GIA’s Smith made headlines in 2016 when he and his colleagues revealed groundbreaking findings within the journal Science exhibiting that very massive and strikingly clear diamonds just like the Cullinan are fashioned a whole bunch of miles deeper inside Earth than 99 p.c of the world’s gem diamonds.

“Diamonds are already an extremely distinctive geological materials,” Smith says. “But even throughout the realm of diamonds, diamonds just like the Cullinan are a particular class that kind in a barely completely different means and have their very own actually distinctive properties.”

Nearly all the usual diamonds that adorn engagement rings and earrings are fashioned round 90 to 125 miles (150 to 200 kilometers) under the floor within the lithosphere, which corresponds to the bottom layers of the thickest sections of continental plates. At GIA, Smith was capable of look at a lot rarer and costlier diamonds referred to as CLIPPIR diamonds, an acronym for the qualities of those prized gems: Cullinan-like, massive, inclusion-poor, pure, irregular and resorbed.

Inclusions are tiny specks of minerals trapped inside diamonds that have an effect on their readability. CLIPPIR diamonds just like the Cullinan have virtually no inclusions, however by analyzing the few impurities he may discover in a whole bunch of huge diamonds, Smith concluded that CLIPPIRs fashioned at depths nearer to 410 miles (660 kilometers) the place liquid steel churns inside Earth’s mantle.

“Tremendous-deep” diamonds just like the Cullinan are thrust to the floor and blended with shallower diamonds throughout a very deep and explosive sort of volcanic eruption generally known as a “Kimberlite” eruption. Kimberlite magma, named after the South African metropolis Kimberley, accommodates extra water and CO2 than common magma.

“It is virtually like shaking a Champagne bottle and releasing all of that strain,” Smith says. “That is the type of vitality we’re speaking about.”

The entire greatest and clearest diamonds on this planet have been recovered from Kimberlite deposits, a lot of them in South Africa, but in addition in Brazil and India, the supply of the fabled Koh-i-Noor diamond. The 105-carat Koh-i-Noor, which implies “Mountain of Gentle” in Persian, was taken from India by the British within the nineteenth century and likewise turned a part of the crown jewels.

As with the controversial Cullinan, the Queen’s dying prompted renewed calls for the Koh-i-Noor to be repatriated to India.