I was trying to trade some red gems the other day with someone but it says the item cannot be traded. I saw some people trying to sell those gems earlier, so I thought it can be traded.
So is it untradable?
right now, yeah on an ‘as is’ basis
you could, however, socket it on a low level gear and trade the gems like that but color gems will drop one rank after being removed from that said gear
Thanks for the response 
What would happen if the gem is already rank 1 though? xD
As of now in iCBT, a level 1 gem can be extracted from an equipment socket for the normal fee. In the kCBT, and likely in the final version, removing a level 1 gem destroys the item (effectively dropping it to “level 0”). This is also the case with monster gems, as (at the moment), they are always level 1 with no way to enhance their gem level.
Thank you for the info