Abstract: The characteristics of the Y-cut quartz crystal plate are discussed. It is shown that by rotating a plate about the X axis special orientations are found for which the frequency spectrum is ...
This amethyst crystal is from Namibia. It shows classic quartz crystal shape: a six-sided columnar crystal with a pyramid-shaped termination at the top. Courtesy Daniel Trinchillo, Fine Minerals ...
Pink, green and blue tourmaline, aquamarine beryl and deep red garnet, purple amethyst and sparkling lepidolite — they all lie buried in Maine granite. To find them, all you have ...