Mineral site, and from there further subdivided by the chemistry of the W site. The Y and Z sites can accommodate a variety of cations, especially various transition metals; this variability in structural transition metal content gives the tourmaline group greater variability in colour. Other cyclosilicates include beryl, AlBeSiO, whose varieties include the gemstones emerald (green) and aquamarine (bluish). Cordierite is structurally similar to beryl, and is a common metamorphic mineral. Sorosilicates, also termed disilicates, have tetrahedron-tetrahedron bonding at one oxygen, which results in a 2:7 ratio of silicon to oxygen. The resultant common structural element is the [SiO] group. The
Gemstone Publishing then to Gemstone, which has been the home of Cochran's EC reprints for over 15 years. Reprinting the Cochran/Gladstone-reprints of "The Haunt of Fear", "The Vault of Horror" and "Weird Science" (all 1992), Gemstone also republished (in single issue and 'annual' - four issues per 'annual' - format): Oversize, hardback, slip-cased collections of these comics had been previously published in black & white by Cochran during the 1980s as "The Complete EC Library". This Library was then added to by Cochran/Gemstone with 2005's "Picto-Fiction" collection, comprising the EC comics: "Confessions Illustrated", "Crime Illustrated", "Shock Illustrated" and "Terror Illustrated", along with