Ok I am not sure what is said about gas in op2. So some one must know.
Could gases or certain groups of gases like the noble gases be used as a resource. I wouldnt put Oxygen as a resource or beable to be collect because certain things need to be out of the players hands and said they are done automaticly or magically.
I'm going to say Yay to the idea of having a gas resource.
it may not necessaryil be one of the raw elements though. I know, logic error -> common metals = light element, rare ore = heavier elements. okay, but what if, just for the gas resource, we have it as a compound (or compounds) that are uber awsome?
We are on an alien venus-like plannet now... the Atmosphere would be filled with gasses an whatnot that could be compounded and condenced into all sorts of usefull things, and even converted into liquid or solid fuel to help the various powerplants more efficient (more for the vehicle powerplants then the colonial powerplants)
Just throwing it out there, I dont expect it to go anywhere though, in an Episode of StarTrek: Voyager, the crew almost believes that they've found a new element. Yes, it was only a biproduct of an alien cultures decomposition, but just perhaps, there can be a whole new table? or just that todays table is a smaller section of a much larger whole, science just doesnt know about in our timeframe and in OP3, they discover it and all the laws of physics and chemistry as we know them are broken... like I said, dumb idea thats likely to be immediatly shot down, but its an idea nontheless.