Gemstone value of the stone. Some treatments are used widely because the resulting gem is stable, while others are not accepted most commonly because the gem color is unstable and may revert to the original tone. Heat can improve gemstone color or clarity. The heating process has been well known to gem miners and cutters for centuries, and in many stone types heating is a common practice. Most citrine is made by heating amethyst, and partial heating with a strong gradient results in “ametrine” – a stone partly amethyst and partly citrine. Aquamarine is often heated to remove yellow tones, or
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."