Mól gem-cleaving / stone-cleaving
The Mól craft of cutting and priming a stone so that an elemental can be put into it, read again off a scroll case in S3E31
The cutting side of the binding-crystals. A stone grown at a planar seam will hold an elemental only if it has been cut for it, and the cut is the whole difficulty: it puts nothing into the stone; it readies the stone so that something can be put in later. Which cuts suit which gem is the substance of the craft. Most stones carry impurities that bias them toward one element and can be cut only for that one. A pure stone carries none and will take any cut there is. The keep beneath Haudh-Gwenn made this its whole specialty, and its workshop is still standing: the magnifiers, the tools, the bins of chips and dust, and the flawed small crystals that did not come out right.
Mikhail cracked a looted Mól scroll case on the road south in S3E31 and found the schematics set out plainly enough to be put back into modern words. Yullen Gemsmith, who cuts stones for a living, later confirmed the reading almost to the word.
The Schematics
The schematics themselves are a Mól working document on the cleaving and priming of stones, decoded out of a scroll case (S3E31). Anybody reading a related document with them to hand has the better of it.