[hdesbois]

Complex ior are great for their subtle effects, but most of them are not very usable in real rendering situations. For instance, gold is obviously pure (24 kt) gold. It would be better to have different flavours of 18 kt gold alloys. A set of the most common metal alloys would be nice too. Maybe some typical gemstones, crystals (such as 24% lead),a variety of coloured glasses...
HD