I have been turned into a vampire and need 5 empty grand soul gems. I have found grand soul gems that aren't empty in the arcane university and magic shops, but the empty ones are especially rare. Does anybody know the locations of these?

Some merchants have one on to sell. You'll occasionally find them in oblivion gates. Personally I've got about 30 hours of game time and have only just found the five.

did they specifically say empty grand soul gems or just grand soul gems? because you might not need empty soul gems. for example, you can turn grand soul gems into black soul gems at the altar but it makes it sound like you need empty grand soul gems. i just tried it out with a few full grand soul gems and all but one turned into dark soul gems (don't know why the last one didn't)

The lady specifies empty ones. But who knows, could be a glitch if she accepts full ones.

Alchemist merchants in the mages guilds, thats where i got all mine. Approx. 350 gold a piece

i have the exact same problem and everything about buying it is cool except for the fact that when you try to talk to a merchant in order to buy soul gems he will cut you off by saying "get back filthy beast" and he wont sell you shit....... so buying the gems is not an option.... post something better bitches...

Drink blood before speaking to merchants and they arnt scared of you. If you can find someone sleeping that is.