Sorry to bump this thread over two years later, but I adore the idea of being able to fabricate glass in an alternative way to just molding it for window pane use.
What spurred the idea on was seeing the use of olivine, amethyst, and rose quartz to make colored glass. I know that historically people discovered that the use of certain element oxides and other compounds would create the pigments they would use for, say, stained glass windows.
My suggestion at least in that regard is to incorporate more chromatology into the creation of the glass during the melting phase, so regular glass can remain more or less the same but getting creative with glass coloration and shaping (for more intricate lamps decorations and otherwise) would incorporate unique workstations, tools, and expending of certain minerals. Alternatively, there IS dye, and seeing Cinnabar be a viable dye option (despite the toxicity which may be superseded by Seraphine "natural" resistances) could already be incorporated into the process.