I'm 'not that happy' with Prometheus (for a variety of reasons) but that's my cross to bear, no one else's. And this thread might be more suited in the Alien forum, but I'll drop it here (mods do what you like with it) . This lingering question might be worth opening a thread topic on, "Are the Egg+Facehugger, the Derelict and the Xeno made of the same stuff?"
It goes back to a thread about what's the best effects-wise Alien in the series... for me, it'll always be the original Alien as it seemed to be made of PEWTER or some other sort of dull living metallic extrusion.
But then if that's so, so is the other stuff in the Alien World.
In fact, even the Prologue Saucer at the start of Prometheus. They're all made of this UGM or Universal Giger Matter, right?