Gemstone the stone such as color zoning (the uneven distribution of coloring within a gem) and asteria (star effects). The Greeks, for example, greatly valued asteria gemstones, which were regarded as powerful love charms, and Helen of Troy was known to have worn star-corundum. Aside from the diamond, the ruby, sapphire, emerald, pearl (not, strictly speaking, a gemstone), and opal have also been considered to be precious. Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a "precious stone" as well, going back to ancient Greece. Even in the last century certain stones such
William S. Stone Paris as air deputy to the Supreme Allied Commander Europe. Stone died while on active duty on December 2, 1968. Stone was a rated command pilot and technical observer. His decorations include the Air Force Distinguished Service Medal with oak leaf cluster, Legion of Merit with two oak leaf clusters, Bronze Star, Air Medal and the Army Commendation Ribbon William S. Stone General William Sebastian Stone (January 6, 1910 – December 2, 1968) was an American United States Air Force Major General and the third Superintendent of the United States Air Force Academy. His final assignment was as the air