Each dragon has a half-page illo.
Basically, orichalcum was a real-world mythological term, which is cool. But it was too difficult to pronounce given the relatively small number of people who've heard of it. At one point, the plan was to change it to cinnabar! (I tried my best to make that not happen.)
Bah!!
Why not call it electrum??!!?!!
If you wanna go old skool, go the whole way!! Don't be a wussy!!!