|This article is about an older version of DF.
Gem setter is the skill associated with the gem setting labor. Gem setters encrust furniture, finished goods and ammo with cut gems. It is not currently possible to decorate weapons and armor with gems, unless the armor is made of cloth. A high level of gem setting allows a dwarf to set gems faster and with better quality, making the decorated items more valuable.
Rough gems, which are found by miners, have to be converted to cut gems by a gem cutter before a gem setter can use them. Large gems, which are sometimes created instead of a cut gems, can not be used for setting as they are finished goods. (You might be lucky enough to be the proud owner of a magnificent <<☼Large (Insert rare gem name here)☼>> (This is a masterful quality large (Insert rare gem name here). This object is adorn with hanging rings of (Insert worthless gem name here).
Because there is a very wide variety of gems in most regions and some types of gems have pretty high material value, adding decorations of different types of gems is a good way to create items with very high value for trade or nobles.
Training gem setters for maximizing value gain
To get the most value out of the gems you find, it is recommended to use up the cheapest gems first (agates, chalcedonies, jaspers etc.) to train your gem setter and leave the more valuable ones (tourmalines, zircons, opals etc.) until he or she reaches a high skill level. The most valuable gems (emeralds, rubies, diamonds, sapphires) should only belong in the hands of a legendary gem setter.
Rough green glass is also a rough gem, so if you have a sand layer on your map it can be produced by yourself from regenerative resources (charcoal) in a regular glass furnace and even from nothing when you are the proud owner of a magma glass furnace. Thus, letting your gem setter encrust everything he gets his hands on with cut green glass is a great way to train him without wasting any of the limited natural-occurring gems.
In order to avoid diluting experience, you should only train a single gem setter (not including successful strange moods), as you will likely not find enough gems for more than one anyway unless you have an army of miners strip-mining the whole map.