The title says it all. I think we should be able to cut jewels down to two 'Gems' that give some of the parent stats. An example, +12 critical (crit) circle onyx. Cutting this would give you 1 +6 crit gem, 1 +3 crit gem & 3 'Onyx Slivers', reagents for new recipes. I think the gems could actually appear on the clothes you embellish (or not if the programming is too difficult). But as a level 49 who recently discovered the, at the time, 199 crown pack for jewels; I have 20 spare square defence jewels that I can't use because my athames & rings are all decked out, the only deck I use has a Locust Swarm Citrine & my amulet is mastery (add slots to mastery amulets!).
A slightly less perfect example, a +19 defence (def) square sapphire. This would half 19 to get 2 9.5s, so one rounds down and the other rounds up. The odd one is always the bigger gem (to slightly cut down on programming), so the 10 becomes a 5 & 5 'Sapphire Slivers'. So 19 def jewel+Cutting=9 def gem, 5 def gem & 5 Sapphire Slivers.
You could even cut it to the 4 jewel shapes. Because I have at least 2 square jewels for each school (except Opal or Hematite ), and nothing to socket them to! It would take a while, but not too long and could entertain us until more plot, worlds & spells. These Slivers could lead to even more crafted items, or possibly just a 'Transmute Onyx'. Either way, I think it would favour most.
critical (crit) circle onyx. Cutting this would give you 1 +6 
who recently discovered the, at the time, 199 crown pack for jewels; I have 20 spare square defence jewels that I can't use because my athames & rings are all decked out, the only deck I use has a Locust Swarm Citrine & my amulet is 
mastery (add slots to mastery amulets!).
defence (def) square sapphire. This would half 19 to get 2 9.5s, so one rounds down and the other rounds up. The odd one is always the bigger gem (to slightly cut down on programming), so the 10 becomes a 5 & 5 'Sapphire Slivers'. So 19 
def jewel+Cutting=11 
or Hematite 
), and nothing to socket them to! It would take a while, but not too long and could entertain us until more plot, worlds & spells. These Slivers could lead to even more crafted items, or possibly just a 'Transmute Onyx'. Either way, I think it would favour most.