A Blue Crystal for Christmas

December 25, 2004


Provided by: Eric Erbe,

  • Beltsville Agricultural Research Center
    Summary authors & editors: Jim Foster

    The above photo of a classic stellar dendrite snow crystal was imaged by a scanning electron microscope, shortly after just falling to the ground. Once a snow crystal reaches the surface, it almost immediately begins to change or metamorphose. The constant jostling and rubbing of crystals against each other causes edges to become chipped and broken -- notice that the lower 3 protuberances of this crystal are displaced slightly from the central hexagonal plate. As the snow settles under its own weight, melts and refreezes and is buffeted by the wind, individual crystals are further altered so after a few days they've little resemblance to their original shape. In general, the crystals are smaller and more rounded. This process is referred to as destructive metamorphism. The blue color isn't natural -- twas added during photo processing.

    Merry Christmas and Happy Holidays!

    Jim Foster and Martin Ruzek

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