Gemstone Publishing is a U.S. company that publishes comic books and collectors\' guides. The company was formed by Diamond Comic Distributors President and Chief Executive Officer Stephen A. Geppi. Gemstone published licensed Disney comic books, starting in June 2003 until November 2008. The company has reprinted EC Comics of the 1950s. Additionally, the company is the current home of The Overstreet Comic Book Price Guide. 
The core of the editorial staff (John Clark, Gary Leach and Susan Daigle-Leach) previously worked at Gladstone Publishing. Archival editor David Gerstein previously worked at Egmont and is author of Nine Lives To Live - A Classic Felix Celebration, a collection of 1920s Felix the Cat comic strips published by Fantagraphics Books.