Soul Gems are one of the many collectibles found throughout Skylanders Swap Force.
There is one Soul Gem to find for each new character. (All returning characters had Soul Gems in previous games.) So that means in Skylanders Swap Force there are a total of 32 Soul Gems to find.
Soul Gems allow you to unlock a special power for the character portrayed on the Soul Gem that you find. Once this power is unlocked it will become available for purchase through the Power Pod.
There is just one Soul Gem for each of the SWAP Force members. This single Soul Gem will unlock a special ability for the top and bottom half of the figure.