Нешлифованный драгоценный камень агат из американского штата Монтана.
Douglas L. Moore (USA)
(This 50x photo shows an unpolished Montana Dryhead agate, found in southern Montana between the Big Horn and Pryor Mountain ranges and just to the west of the Big Horn River. It won 12th Placein the 2014 Nikon Small World Photomicrophotography Competition, which recognizes excellence in photography with the optical microscope, and was taken by Douglas Moore of the University of Wisconsin - Stevens Point in Wisconsin, USA, using axial lighting provided by Leeds fiberoptic illuminators.)