Lomine, my thoughts exactly lol what feed store chick would be rare? I mean next time I'm out in the pen I'm going to tell her that thoughIt is her black comb and such that really threw me off. In any case, I sure like the way she looks too. I might name her Puzzle because she truly is.
All the Asia Black chickens I see images and descriptions are with a red comb so not sure about that but the white down her front does match that bird.
A black comb can simply be from a inherited Fm gene , not that uncommon in black based birds, although seen mostly in silkies.