Turns out diamonds have powers beyond bringing bling-happy jewelry enthusiasts and hopeful lovers to their knees. Harvard researchers have figured out how to make the shiny little pebbles into the world's tiniest thermometers. How tiny? Small enough to take the temperature of an individual cell.
While you might call it "ice" (and please, if you do, stop) diamond is actually an excellent heat conductor. When blasted with green laser, nitrogen impurities inside diamond particles emit red light that changes intensity depending on temperature. This behavior, discovered accidentally by researchers studying quantum computing, led scientists to inject nano-sized diamond crystals into cells and analyze the red light to measure internal temperature. They found that the diamond thermometers are 10 times as sensitive as other techniques, able to detect changes as small as 0.05 degrees Celcius. The diamond particles can even let scientists compare temps between two parts of the same cell.