GIA Reveals Why Diamonds Are Blue

RAPAPORT… Blue diamonds may get their color from traces of boron
contained in the floors of ancient oceans, according to research by the
Gemological Institute of America (GIA).



The research lab studied mineral inclusions in 46 blue diamonds
submitted to the GIA for grading over a two-year period.


The group, led by GIA research scientist Evan Smith, found
that these stones originated at depths reaching 410 miles or more into the earth’s
lower mantle. The diamonds formed in deeply sunken, ancient oceanic tectonic
plates. The scientists believe the boron made its way to the earth’s interior
through movement of those plates.


“Blue diamonds, like the famous Hope diamond, have intrigued
scientists for decades, but the rarity and high value of these gems and their
near lack of mineral inclusions have been major hurdles to research,” said
Smith. “The opportunity to study these rare diamonds at GIA gave us insight
into their incredible origin.”


GIA conducted the study together with researchers from the Washington-headquartered
Carnegie Institution for Science, the University of Cape Town, South Africa,
and the University of Padova in Italy. The results were published in the
scientific journal Nature.


Image: The famous 45.52-carat, blue Hope Diamond, named after the
Hope family, which owned the stone in the 19th century.
Credit: Granger Historical Picture Archive/Alamy
Stock Photo