The Diamond Glass is a non-transparent glassy building-block that glows in the dark/night. It can be crafted in your Crafting Menu (default key "Q") or at Crafting Tables (that still exist in worlds created before R22 on September 16th 2015), but only after the crafting-recipe has been unlocked upon taking a Diamond (bar) for the first time (out of a Forge for example). To craft 8 (blocks of) Diamond Glass at a time, you'll need (as of R29 in February 2016):