Kimberlite and of those just over 30 have been economic enough to diamond mine. The deposits occurring at Kimberley, South Africa, were the first recognized and the source of the name. The Kimberley diamonds were originally found in weathered kimberlite, which was colored yellow by limonite, and so was called "yellow ground". Deeper workings encountered less altered rock, serpentinized kimberlite, which miners call "blue ground". See also Mir Mine and Udachnaya pipe, both in the Sakha Republic, Siberia. The blue and yellow ground were both prolific producers of diamonds. After the yellow ground had been exhausted, miners in the late 19th
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.