How to fill a black soul gem? [duplicate]

So, I have to fill this black soul gem for Falion, so I killed a few Draugr and used Soul Trap on them within the 60 seconds but it didn't fill it?

I emptied out all of my other empty soul gems and still nothing happened? Does it have to be a human that I have to kill? I don't think I have long until I'm a 'Stage 4' Vampire?


Solution 1:

Black soul gems can hold humanoid souls, (and the same souls that white/regular soul gems can hold), while white/regular soul gems can only hold the souls of lesser creatures.

Taken from the Skyrim wiki:

Black souls are those of sentient, humanoid beings such as Imperials, Argonians, Khajiit and Dremora, while white souls are those of animals and certain lesser Daedra.