I enchanted an ebony bow with a black soul gem. The only qualitative difference I see is in the the amount of charge and in that I could sell it for more if I wanted to sell it. The downside is that it takes several common souls to recharge the thing.

I've now collected two more but they're sitting in a chest in Markarth because I don't want to accidentally trap a mudcrap in one of them.

I also understand that only humans and other humanoid races count as black souls; is that correct?

At any rate, I'd really like to know how to get the most out of them.

Thanks.

if you accidentally trap a low soul in them, you can drop them on the ground to empty them.

You should keep soul gems of different sizes in your inventory to prevent this problem. Though as the other poster said, it's easily solved by dropping the gem on the ground. The other safeguard is that you keep your soul trap weapon or spell only for certain instances. I like trapping necromancers or Thalmor in their own black gems.

Also, you didn't say what enchantment you put on your bow. If it's something like soul trap, the size of the soul gem will only make a difference in how much charge there is. Something like % damage will change based on the size of the gem you use to enchant, also on fortify enchantment potions.

A grand soul with a cheap enchantment will only make it so there are a ton of hits before you need to recharge it. Go learn some nice enchantments, level up your enchanting skill, and add perks to see your enchantment itself get more powerful. The gem is the paintbrush, the enchanter is the artist. A really nice paintbrush won't make a masterpiece, but a great artist can.

Also, if you want a Black Soul Gem with a Grand soul, just go to any bandit lair and soul trap a bandit. Easiest grand soul ever. Meanwhile, getting a grand soul for a normal gem is much harder.

http://elderscrolls.wikia.com/wiki/Black_Soul_Gem_(Skyrim).

For some reason, the last ')' in the url didn't wanna get joined to it, and had to do that to get the link to work.
According to that page, Black Soul Gems can trap White Souls.

My enchantment skill for the character I'm thinking of has 90+ enchanting. I have some things laying around that could use some enchanting... Dragonscale armor, two full sets of ebony armor, glass armor, and pretty much every kind of decent non-Daedric weapon that exists in the game. But mainly I wanted something for the character. Money really isn't that much of an issue anymore. It'd take me at least an in-game month to sell off all the crap I've pack-ratted into my houses.

I guess I'll just go for a nice necklace with a strong pickpocket enchantment on it. This character was a pure mage but I'm converting him to a thief/assassin so his skills in those areas are pretty pathetic. I already made him a ring with a 35% sneak enchantment and that's worked pretty well.

At any rate, I was just wondering if maybe there was some extra-special thing I could do with black soul gems that aren't possible with any other type. Apparently not; they're just the most powerful soul gem.

Oh, and thanks to everyone about the soulgem dropping tip. I didn't know that. The next time I play, an icewold is coming out of a grand soulgem.

BTW Mammoths are grand souls; Giants are greater souls; you cannot trap dragon souls; mudcrabs don't have souls.

I use black soul gems for those who p*** me off. I've got 20 of them... filled.

Souls.... waste not want not.

No I didn't make one out of Mede II. I figured that would be a lesser soul.... milk drinker. Astrid on the other hand.... I just wish the game kept track of who is in which gem, but then people would complain about them not stacking and how so and so should be worth more than someone else.

Always buy empty soulgems when vendors have them for sale.

After you've got a ton of gold you can start buying filled ones.

Sonja.... I get petty souls from mudcrabs, skeletons, wolves, etc.

Mudcrabs have petty souls. I've captured hundreds of them. One time I had 20+ steel daggers so I went out and captured 20+ mudcrab souls; got about $250 a pop.

Not to mention that chitin is one ingredient for Cure Disease potions....

Save your Black soul gems, late in the game you'll find a use for them (regular Grand soul gems won't work for it)

ps - the Black gems don't even need to be filled

Having run out of low level gems I went out on a soul harvesting mission yesterday and found that mudcrabs, wolves, bears and sabre-cats have become extinct in the area around Whiterun. I was out all game day and all game night and saw nothing, other than a couple of mammoths (which I don't touch on religious grounds); yet the area used to teem with souls for trapping. Does anyone know if its possible to empty an area of game and how long, if ever, they take to re-populate an area.

The Black Star is pretty great, kill a random guard and recharge your weapon. The only creature with grand souls I can think of are Mammoths, which are farmable.

And... like... Dremora or something. Four respawn at Dagon's shrine, but who's easier to kill? A bandit, or a mammoth? A guard, or a Dremora?

I stole this idea from someone on this forum but I've been killing named characters and use their souls to enchant weapons or armor that I name after them

I've always left the chitin. I'm a werewolf. We don't need no steenking cure disease potions.

Draugr. Plenty from Draugr, too. I don't know if they're lesser or petty. It's hard to keep track. Too much junk in the inventory. I may have missed the mudcrab with the soul trap spell. I've missed before. Nothing new.

I've noticed that Briarhearts usually have a black soul gem on them that is unfilled.