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 Publishing Gemstone Publishing Gemstone Publishing is an American company that publishes comic book price guides. The company was formed by Diamond Comic Distributors President and Chief Executive Officer Steve Geppi in 1994 when he bought Overstreet. Gemstone published licensed Disney comic books from June 2003 until November 2008. The company has also reprinted EC Comics of the 1950s. BOOM! Kids acquired all comic publishing licenses regarding Disney characters in the second half of 2009. Gemstone's flagship publications were comic books featuring Disney characters; particularly the Donald Duck/Uncle Scrooge comics of such Duck artists as Carl Barks and Don Rosa, and the