Garnet pegmatite and allied rock types and in certain low grade metamorphic phyllites. Spessartine of an orange-yellow is found in Madagascar. Violet-red spessartines are found in rhyolites in Colorado and Maine. Blue pyrope–spessartine garnets were discovered in the late 1990s in Bekily, Madagascar. This type has also been found in parts of the United States, Russia, Kenya, Tanzania, and Turkey. It changes color from blue-green to purple depending on the color temperature of viewing light, as a result of the relatively high amounts of vanadium (about 1 wt.% VO). Other varieties of color-changing garnets exist. In daylight, their color ranges from
Gemstone File Originally distributed in 1975 by hand and mail in photocopy form, the Gemstone File has appeared in slightly revised form in Hustler magazine and on the Internet. Roberts, known only to Stephanie Caruana and conspiracy theorist Mae Brussell, purportedly began gathering information in the file when Howard Hughes stole his invention for processing synthetic rubies, hence the title "Gemstone". According to Gerald Carroll, Roberts was born in New York State on October 27, 1919 and died of lung cancer in San Francisco on July 16, 1976. "Factsheet Five" publisher Mike Gunderloy collected and distributed several versions of the Gemstone File.