Inside a secure laboratory in New York City geologist Evan Smith is peering into billion-year-old blue diamonds to gauge the inner workings of Planet Earth.
The cold, dense objects zap the warmth from his hands. They come in a range of hues. “Some are so pale you wouldn’t know they’re blue, some get a gray tone along with the blue, so they can look a little mysterious,” says Smith, who works in the diamond-grading lab at the Gemological Institute of America
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