|This article is about the current version of DF.|
Dwarves with the glassmaking labor enabled can use a glass furnace to produce a wide array of objects. Almost all furniture can be made here (beds, millstones, querns, and slabs are the exceptions), as can blocks, trade goods, gems (in the form of raw glass), and a few items which can only be made of glass:
- Vials - These are necessary for acquiring certain extracts at a farmer's workshop, and can also be used in place of flasks or waterskins.
- Windows - These function much like gem windows, but are also necessary inputs in the production of display cases.
- Instruments - Depending on the specific outcome of your particular world gen, you may be able to produce unique instruments and instrument pieces here. Produced glass instruments will always be made of green glass, but caravans may bring clear and crystal glass instruments for trade.
Some glass items are functionally identical to items of different materials, but have different names. A glass door is called a "portal," a glass coffer is called a "box," a glass pipe section is called a "tube," and a glass cage is called a "terrarium" or "aquarium."
Glass furnaces are also needed to issue the "Collect Sand" order. Doing so requires an empty bag, an Item Hauler, and a zone designated for sand collection. As the "Collect Sand" order will prevent other furnace tasks from being started until the sand is collected, it is often wise to build several additional glass furnaces, magma or otherwise, to use for the collection of sand. Not all maps will have a source of sand, but sand may be imported in small quantities. Caravans can also bring raw glass gems for trade, which can be particularly useful for dealing with strange moods.
Producing glass items requires working with raw materials, though the specific materials are determined by the kind of glass you wish to produce. Green glass goods are simple, requiring only a single bag of sand - the color of the sand makes no difference on the finished product. Clear glass goods are more complicated, requiring a bar of pearlash in addition to the sand. Crystal glass replaces the sand with an uncut rock crystal gem, while still requiring the bar of pearlash. Rock crystal is not present in most regions, and is very limited on those maps it does generate on, making production of crystal glass goods a rarity.
Additionally, all reactions at a glass furnace consume one unit of fuel.
Glass furnaces can be built from any fire-safe material. Once you designate a spot for your furnace to be built, a building designer will bring the material to the site and design the building before the actual mason (for stone and glass furnaces) or metalworker (for metal furnaces) comes along and builds it. Strangely enough, charcoal and coke are valid mason's materials for building a glass furnace, since their ignition point is above the cutoff for fire safety.
The overall value of the glass furnace building helps determine the strength of the good thought dwarves receive when admiring it. This value is determined by both the value of the material used in its construction, as well as the quality of both the architect's and builder's efforts.