Soul gems are gems that can be used to capture the souls of men and beasts. There are a number of different soul gems, each of which has its own maximum soul energy and can only hold certain types of souls. Black souls are the souls of men, mer, and the beast races. All other creatures have white souls. Soul gems have an ENC of 0.
Characters can also purchase soul gems that are completely, or only partially, full. The price of filled soul gems can be determined with the following formula:
Filled Soul Gem Price: Gem Price + (Gem Price × [% full, as decimal])