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
Gemstone File Gemstone File The Gemstone File is a conspiracy theory document attributed to Bruce Porter Roberts. In 1975, "A Skeleton Key to the Gemstone File" appeared and is generally attributed to Stephanie Caruana. The "Key" is purportedly a synopsis of Roberts' documents that presents a chronicle of interlocking conspiracies, including claims that world events since the 1950s were shaped by suppressed information, the names of supposed shooters of President John F. Kennedy, and suggested connections between a number of political assassinations which occurred within a relatively short time frame. Authors James McConnachie and Robin Tudge called it "the original mega-conspiracy theory."