Search This Blog

Tuesday, December 23, 2014

Rock Contains 30,000 Diamonds

Researchers have unveiled a strange ornament-sized rock from near the Arctic that’s red and green and comprised of diamonds. Nearly 30,000 colorless micro-diamonds, to be exact. The findings were presented this week at the American Geophysical Union fall meeting in San Francisco. 

The 30-millimeter, 10.5-gram rock was a sparkly donation to science from the owners of Siberia’s Udachnaya diamond mine, which is dominated by volcanic xenoliths (Greek for “foreign rock”) with a few precious “diamondiferous” ones. Among these was a unique diamondiferous xenolith with garnet and olivine to give it those Christmas hues. A team of researchers from the U.S., Germany, and the Siberian Branch of the Russian Academy of Sciences created 2D and 3D images of the strange rock using high-resolution X-ray computed tomography (which is similar to a medical CT scan). These images revealed the relative abundance of its various mineral parts, and diamonds made up 9.5 percent by volume. 
The micro-diamonds were between 100 and 700 micrometers in size, and many of them occurred in clusters. With millions of carats per ton, this is the absolute highest yield of diamonds ever in a mantle xenolith, the researchers write. Typical diamond ore averages between 1 to 6 carats per ton (a carat is about a fifth of a gram). But being so tiny, these diamonds weren’t worth much as jewelry.