Oblivion Grand Soul Gems
Grand Soul gems are very useful in Oblivion. The most obvious way is that they can help you enchant your weapons to their max potential. However, these soul gems are very difficult to find, therefore the majority of this page is about grand soul gem locations.
Uses
Grand soul gems are like any other soul gem except they are a lot stronger than their predecessors. They allow you to capture grand level souls and carry a lot more charge than other soul gems. So, you can enchant weapons with attributes that need a lot more charge than others.
Locations of Oblivion Grand Soul Gems
Like other soul gems grand soul gems can be found in various mages guild halls. They can also be found in the Arcane University. Two grand soul gems may be purchased at the magic store in the Imperial City Market District. Others may be found at various Elven Ruins. Another way to gather Grand Soul Gems is to pickpocket member of the mages guild, just don't get caught and save after everytime you successfully pickpocket someone. Otherwise, just search caves and dungeons.
Vampire Cure Quest
To get an easy soul gem for this quest just go in the ladies (lady that is making you your cure) basement which the trap door is located near the fire place and there will be a grand soul gem there, too.
Other Help
Please visit oblivion grand soul gem for more information.