Well, after reaching 100 craftpoints in a certain Tier, the artisan gets a chance to create "special" items (like mentioned
here)
But mentioning the jewels gives me several ideas. Ofcourse, I suppose it has already been foreseen by developers, but this doesn't prevent us from brainstorming several suggestions:
To start with, we might have the option of adding a polished agate, emerald, opal or topaz (or whatever) to an item we craft for more armor/primary skill (for all "clothing" items), armor/block (for shields only), damage/primary skill/critical for weaponry (or damage/primary skill/ critical/ block, if it is a sword).
But, in order not to collide with the ideas of rare, legendary and epic items, only ONE of the options can be available, e.g:
An armorsmith can craft a sword or:
1) the same sword with +1 (or 2) attack skill for 2 (or 4) topaz
2) -/- +1 (or 2) agility skill for 2 (or 4) opal
...
5) +2% (or 5%) critical chance for 1 (or 2) of each type of refined gems
6) +5% (or 10%) of the basic block of this weapon for 1 (or 2) of each type of refined gems
7) +5% (or 10%) of the basic damage of this weapon for 1 (or 2) of each type of refined gems