GIA Reveals Why Diamonds Are Blue

RAPAPORT... Blue diamonds may get their color from traces of boroncontained in the floors of ancient oceans, according to research by theGemological Institute of America (GIA). The research lab studied mineral inclusions in 46 blue diamondssubmitted to the GIA for grading over a two-year period. The group, led by GIA research scientist Evan Smith, foundthat these stones originated at depths reaching 410 miles or more into the earth'slower mantle. The diamonds formed in deeply sunken, ancient oceanic tectonicplates. The scientists believe the boron made its way to the earth's interiorthrough movement of those plates. "Blue diamonds, like the famous Hope diamond, have intriguedscientists for decades, but the rarity and high value of these gems and theirnear lack of mineral inclusions have been major hurdles to research," saidSmith. "The opportunity to study these rare diamonds at GIA gave us insightinto their incredible origin." GIA conducted the study together with researchers from the Washington-headquarteredCarnegie Institution for Science, the University of Cape Town, South Africa,and the University of Padova in Italy. The results were published in thescientific journal Nature. Image: The famous 45.52-carat, blue Hope Diamond, named after theHope family, which owned the stone in the 19th century.Credit: Granger Historical Picture Archive/AlamyStock Photo