cock or hen

Hi all, we got 4 hens off a farmer begin of jan, all fine. Were given 2 chicks a few weeks later, no idea of age, think they are bantams, anyway, they are all in together after a bit of squabbling, 1 is noticably smaller than the other, could the larger one be male? its about the same size as the hybrids, larger comb than other one and its crop is bigger than ALL  the others, no crowing though, its a lovley looking bird, black with blue and some gold on back, and gold round the neck, if it is male, what age do they start crowing??   cos if it does i wont be able to keep it

Love to see a picture of him/her Chelle, sounds beautiful