Augmenters: These fabrials are crafted to enhance something. They can create heat, pain, or even a calm wind, for instance. They are powered-like all fabrials-by Stormlight. They seem to work best with forces, emotions, or sensations.
The so-called half-shards of Jah Keved are created with this type of fabrial attached to a sheet of metal, enhancing its durability. I have seen fabrials of this type crafted using many different kinds of gemstone; I am guessing that any one of the ten Polestones will work.
Diminishers: These fabrials do the opposite of what augmenters do, and generally seem to fall under the same restrictions as their cousins. Those artifabrians who have taken me into confidence seem to believe that even greater fabrials are possible than what have been created so far, particularly in regard to augmenters and diminishers.
Conjoiners: By infusing a ruby and using methodology that has not been revealed to me (though I have my suspicions), you can create a conjoined pair of gemstones. The process requires splitting the original ruby. The two halves will then create parallel reactions across a distance. Spanreeds are one of the most common forms of this type of fabrial.
Conservation of force is maintained; for instance, if one is attached to a heavy stone, you will need the same strength to lift the conjoined fabrial that you would need to lift the stone itself. There appears to be some sort of process used during the creation of the fabrial that influences how far apart the two halves can go and still produce an effect.
Reversers: Using an amethyst instead of a ruby also creates conjoined halves of a gemstone, but these two work in creating opposite reactions. Raise one, and the other will be pressed downward, for instance.
These fabrials have only just been discovered, and already the possibilities for exploitation are being conjectured. There appear to be some unexpected limitations to this form of fabrial, though I have not been able to discover what they are.