Soul gems are used for harvesting the souls of nonsentient creatures and then binding them into the gem. This bound soul can then be used for enchanting weapons and armor, or other purposes of the arcane.
The grand soul gem is the largest soul gem, and can carry any size of white soul. When filled with the best applicable soul, their capacity utilized in enchanting is 1600.
Grand soul gems can always be found in the following places:
- Chorrol Mages Guild Hall – Two are located in a display case on the main floor (Very Hard lock). There are also three more in another display case. When the Hero first enters, they are through a door to the left. (Some are not empty in the PS3 GOTY version)
- Arcane University – One can be found in a display case (Very Hard lock) next to a couple of other Grand Soul Gems (which are not empty). The Hero may also find three more in the Arch Mage Lobby. Another can be found in a display case (Very Hard Lock) in the Arcane University Mage's Quarters. Another one may be found on a desk on the second floor of the enchanting building. (Not empty in the PS3 version)
- Drakelowe – Located in the basement (accessed through trapdoor in the fireplace). (Not empty in the PS3 version)
- Crayfish Cave – Down the Corbolo river to the south-southeast. Three are located in various areas inside the cave.
- Nornal ruin – Directly west of Drakelowe. On the map it is just left of the capital "N" where it says "The Nibenay Basin."
- Squandered Mine – Northeast of Drakelowe. Located behind a secret door on the bottom level, guarded by an undead creature.
- Swampy Cave – Swampy Cave Dry Rock Run specifically, just head south a bit from SC to find this entrance. The gem is located in one of the chests in the large room where there are two swamp trolls. (Not empty in the PS3 and 360 versions) (Not present in the PC version)
These are easily located sources, but may not always have a grand soul gem available:
- Buy from Aurelinwae or Calindil in the Mystic Emporium, Imperial City Market District.
- Most Mages Guild Halls will have at least one grand soul gem for sale.
- These may also be pickpocketed from the merchant.
- 4 gems can be obtained via the quest "Sins of the Father," but they are not empty.