I love the idea of the current Transmute Mineral Ore spell that's currently within the game, the only nuisance is that I cannot use it to get a lot of silver ore from the iron, since it automatically turns any silver into gold. Is there a similar in game spell available or a mod that offers more options when it comes to transmuting ores?

A container. Place what you dont want changed into there and there you have it.. Otherwise, no.

It's crap the way they do it.. Iron to silver needs priority. Hopefully it's a scripted spell and the CK will let us change it.

Let's hope so, I would be ok with 1 transmutation spell if they fixed it like you suggested!

That's not really a bug, it is working as designed atm, near as I can tell. Tthe spell is transmute iron or to silver or transmute silver ore to gold, with silver ore in inventory taking precedence over iron as to what gets transmuted first. What you want is separate transmute spells, or else a different interface where something could pop up to ask you want you want to do, like the enchantment interface. Personally, I just drop silver ores or quickly create ingots from them before transmuting more. It's not ideal, but personally I would rather not have transmute 1 and transmute 2 etc., spells listed, for spells I don't use much.

I do the same thing, wouldn't consider it a bug either. Sometimes I want gold, sometimes silver. But considering the time to regen, I just find a place where there aren't people (ie. home or the forest) and drop it on the ground. Hassle... in a way, but would be annoying to have different spells for a very similiar thing.