Actually you need 5 UUM for Gold and 7 UUM for Iridium.
In reality you won't find Iridium alone, but combined with some other metals (which are similar in value). Unfortunatly IC2 doesn't have any of these materials so an easy substitute is gold. The problem is that you will definatly waste the gold (in reality you would filter the Iridium out of the gold).
What you do is put 4 gold-dust together and melt it inside a furnace. Gold smelts at 1337K (really... it is 1337, which makes gold that awesome) and Iridum at 2739K. So the gold will smelt and the iridium will remain, actually the gold isn't as heavy as iridium so it's on the surface (thats rather basic^^).
I don't know if Alblaka wants a substitute for the UUM-Version of getting Iridium, but 2 Gold-Ore seems to be a fair deal, although I would like a little bit more metals in IC2 I understand why it's kept simple.