DR JUERG ALEAN / SCIENCE PHOTO LIBRARY DR JUERG ALEAN / SCIENCE PHOTO LIBRARY
Double-ended quartz crystal. So-called 'phantom structures' in the left part of the crystal show successive stages of growth. As the crystal grew, clay minerals were deposited on the surface of the quartz crystal, but later became embedded as the growth continued. This specimen, about 3 centimetres across, is from the Lugnez valley, Grisons, Switzerland.
Model release not required. Property release not required.