not all gear is upgradable
either check the wiki for your armor
or list it here, and i'm sure someone can help you.
and just to let you know.. i don't think it's worth upgrading 2 star or lower equipment (unless it has a good UV)
it's better to buy a 3 star from the AH
how about a tempered calibur?
okay. But how do i check what the upgraded gear is?
To find the upgraded version of Tempered Calibur;
Simply look through all recepies you encounter at Basil (the guy in the terminals in the clockworks) and se if any of them needs the Tempered Calibur to be crafted.
Of simply look at the Wiki..
the recipe for the calibur series can be brought from Kozma in the bazaar
All you have to do is buy the upgraded gear's recipe then take the materials needed to the alchemy machine, pay the fee, and then your new gear is created.