I got the black/yellow color stone for pre-ordering The Old Republic, but I look a little unbalanced as a Jedi Sentinel with two lightsabers — the other is blue. As such I was hoping I could convince someone to trade me theirs, but I don't know if this is possible due to the special nature of the item. Can it be traded?
You can buy another color crystal on the Republic (or Imperial) fleet. Use your map, click the Vendors button to show vendors, and look for the Pre-order Crystal Vendor tucked in a corner along the outer circle.