[the phantom]

Which volume of HoME is it in?

It is in Volume X (Morgoth's Ring).

Although that question is somewhat meaningless, as I [very ashamedly] will admit to not having read any of HoME. But I do plan on ordering them through my local library once I have some free time again...

Well, if you manage to find the time (I never knew a teenage artist's schedule was so cramped) then you should read Volume X. It's definitely the best one (in my sometimes almost humble opinion).

But I'll give you a taste of the book real quick here. Tolkien wrote this at one time but crossed it out-

Here they dwelt for a year, and here Indis wife of Finwe bore him a son, eldest of all the second generation of the Eldar.

This was right before they crossed the Misty Mts (and you'll notice the name Indis was used instead of Miriel).

And then Chris Tolkien wrote this a bit later-

The two passages concerning Indis wife of Finwe...are notable as the first indications of what would become a major further development in the Valinorian legend, though the stories told here bear no relation to the later narrative. These briefly sketched ideas may have been merely passing, rejected as soon as jotted down; but they show my father's concern with Feanor, feeling that the greatness of his powers and formidable nature were related to a singularity of origin- he was the first-born of the Eldar: that is to say, he did not 'waken' by Kuivienen, but had a father and mother, and was born in Middle-Earth.