Not much of an idea but, I was thinking it would be cool if floating island had a special type of ore in them; example Aluminium Ore. This ore would look somewhat like silver or iron but it would not have the same properties. Instead I was thinking that maybe you could make a vanity set with it or even better. I was mainly thinking about this when I was farming mobs and I was thinking that maybe when refined with iron, copper and silver it could attract items within 5 blocks. Wouldn't it be cool to have small magnets in terraria XD.
I think Aluminum Ore would be a fairly useful addition to the game, more useful for furniture and other aesthetic building blocks as opposed to tools or armor, a few exceptions could be made though; An aluminum baseball bat for example. I mean who wouldn't want to smack a slime around with a baseball bat? The magnets are a pretty decent idea also, at this time I'm not sure what it'd attract aside from coins, but it'd be very neat as a tool to help find iron deposits!
Not sure about the vanity set idea, sure having more vanity sets is never a bad thing. Magnets could be a nice feature, except if you mean actual dropped items then a way higher range would be nice and usefull for like farming machines. The problem on most of this is on the quantity of floathing islands or "sky biome" at all. It would be nice if we had an entire sky biome that is, but adding it only on floating islands would not be as effective as it could easily force you to get into other worlds just to farm it.
I wanted to make sure that this material couldn't be farmed with spleunkerer pot. This way Aluminium would be worth a lot more than copper, iron, silver, gold. I tried not to make it to overpowered =S
Well it's definitelly not overpowered. The real problem is how much of it could spawn on a single world. I'm not sure if it would really fit if there is no real "sky biome overhaul", unless we have it as a really limited ore, in that case it could work enough. Also I don't think spelunker would change much either way a floating islands are quite nicelly lighted up at daytime for the most.