First of all...congrats on getting this perfect piece. It is certainly not easy to come by considering this is a gen1 Tio2. The color contrast(lighter & less shiny) and the texture(rougher) you just described on the plasma, the OF termed them as 'bone' plasma as it resembles that of a dried and clean bone.Received them and they are in perfect condition. They look brand new, not even any marks from cleaning on the lenses. I've never seen the xmetal finish in person, it's definitely not carbon though in photos they look like a darker grey/black. The plasma looks different than my plasma Juliet. It's more grey and less gold. Also has a slightly more rough texture to touch than the plasma of my Juliet.
I love the larger lenses of the XX, I've always thought the Juliet are a little small for my face but the XX are perfect.
However do take note that the material is somewhat more porous and it will stain more easily as compared to plasma material of the later batch where it is lacquer or sheen protected. The bone plasma needs to be cleaned immediately as adviced should you happen to have perspiration on them. If left unattended, yellowish pigmentation will form and in due course, the stain cannot be removed.
Just sharing some TLC with ya. Hope these helps!