August 02, 18
by Staff Reporter
(IDEX Online) –
Blue diamonds, among the rarest of all colored diamonds, form at extreme depths – approximately four times deeper than most diamonds – and may get their color from a surprising source, the GIA said in a statement.<?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-com:office:office" /?>
It is known that the element boron gives the diamonds their color, but new investigations show it is contained in the floors of ancient oceans carried deep into the Earth’s mantle by the movement of tectonic plates, according to new research featured on the cover of Nature
, a distinguished international scientific journal.
It was the first study to examine and identify the mineral inclusions in very rare and valuable blue diamonds. Analyzing those inclusions demonstrated that the diamonds formed at great depth in the presence of sunken, or “subducted,” ancient oceanic tectonic 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 GIA research scientist Dr. Evan Smith, the lead author of the Nature
article. “The opportunity to study these rare diamonds at GIA gave us insight to their incredible origin.”
Blue diamonds, also known as type IIb diamonds, derive their color from minute quantities of boron. The study reveals that blue diamonds originate from depths reaching 410 miles (660 km) or more into the Earth’s lower mantle, where boron is scarce. Mineral inclusions in the blue diamonds show that they formed in deeply-subducted oceanic plates. The authors of the study hypothesize that...
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