All black feathers have iridescence, no matter the breed, gender, species... all black feathers. Even the black tips to my spangled hamburg's feathers sheen in the right sun. Its just a trait in black feathers.I think females do actually get them, they just aren't as eye catching. I also think they don't develop as fast as they do in males, but I could be wrong. I have two ayam cemani chicks and the female does have iridescent feathers, but they came in much later than (we think male, I should post a thread.) our male did.