Analysis reveals strange chemical composition
Diamonds, they say, are a girl’s best friend. You would think then that finding a rock crammed with 30,000 of the precious gems, as did miners at Russia’s huge Udachnaya diamond mine, would mean hitting the jackpot. Unfortunately for them, the diamonds’ tiny size rendered them worthless as gemstones. Fortunately for science, though, the miners donated the rock so that researchers could examine the baffling stone, which has a diamond composition millions of times denser than typical diamond ore.
“The exciting thing for me is there are 30,000 itty-bitty, perfect octahedrons, and not one big diamond,” Larry Taylor, a geologist at the University of Tennessee, Knoxville, told LiveScience. “It’s like they formed instantaneously.”
The rock itself is both red and green in hue (just in time for Christmas!). That, combined with its outrageous diamond density, has scientists scratching their heads for now, but will ultimately provide insight into Earth geologic history. While the process behind diamond formation is understood such that they can be created in a lab, a stone with so many tiny, identically-sized gemstones may help reveal previously unknown facets of the mysterious natural processes.
“The associations of minerals will tell us something about the genesis of this rock, which is a strange one indeed,” Taylor said. “The [chemical] reactions in which diamonds occur still remain an enigma.”
We know that diamonds require colossal amounts of heat and pressure to form, and indeed they’re believed to originate in Earth’s mantle. Unfortunately, diamonds are so rare because the violence of the volcanic eruptions that carry chunks of diamond-rich mantle to the surface usually results in their destruction.
Using what’s known as an industrial X-ray tomography scanner, scientists were able to image the stone to find thousands of diamonds tightly gathered in bands throughout the rock. Electron probing further examined inclusions within the small diamonds, finding that they most likely formed from fluids that escaped from subducted oceanic crust. Other gems identified include garnet, olivine and pyroxene minerals.
The chemical analysis is unusual, but another scientist not affiliated with the study offers a simple explanation – the stone could just be a really, really old formation that’s been trapped in Earth’s mantle for a long time.
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