Fire Glass #4 Pearl (Blue Glow in the Dark): There will be variations in color, shade, texture, and size. Final selections should be made from actual glass sample and not from glass samples or color reproductions. Consumer should inspect glass before installation. All glass MUST be set with any high-grade, flexible mortar system (Latex modify thinset). All glass MUST be installed according to ANSI A 108.16 installation specifications.