MILK: Elven-rope is as soft as this.
IRON: Nori runs back! It’s well hard.
TILKAL: Not acid, and mingles without note. Initially titanium, and six of these helped produce this seventh one.
HITHLAIN: Here without hesitation, reclined; it binds.
N
ROVLAG: Gone to the toilet in slang? Must have been in a hurry, as got mixed up, ran backwards and overshot! Blame the Dark Elf for the result.
ITHILDIN: One emaciated top mingles for this substance.
LEBETHRON: Napoleon’s isle and royal seat? Loses note in confusion.
Yes, Aule took 6 metals and from them made a seventh, TILKAL, harder than all the rest, and from it forged Angainor.
Just the T (the initial of Titanium), plus alkali minus A.
I had to include 2 substances also around in our own age to make a password, though.

I did think of adding a reference to Dain Ironfoot to make the Iron one more Middle-earthish, but there was iron in Middle-earth and there was a mention of Nori. Milk already is because it's part of Sam's elven-rope simile.
Well done both, and over to Galadriel!