Socketing a Superior armour won't work with TalThulPTopaz?

[DukeZed]

I'm trying to use this fancy cube recipe on this Superior armour I found but it won't work for some reason? The armour is Superior 8%ED ethereal non-socketed Dusk Shroud with Tal Thul PTopaz in the cube, but nothing happens when I click the button. Looking at the recipes page, it says 'normal armour' does this mean no superior and no ethereal (heck not even a crude) armour is accepted for the recipe only white plain ones?

[kuafu]

Cube recipe doesn't work on superior items, but it works on ethereal items.