I did some research and I believe I found out what’s going on with the black spots on the face/comb. It’s something called melanosis. It’s a genetic trait that causes the skin to appear darker in patches or on the entire bird. There are different variations manifest differently, but based on...
This is the australorp. Not sure if it's just the light that's making her eye look a weird color (edit: I think it is the light). I'll check that tomorrow. Her eye has always been shaped like this.
This is the sapphire gem. As I noted earlier some of the marks near the back of the comb are from some sort of fighting. But near the front of the comb, on the rest of the face, and on the earlobes I'm not sure what is going on.
I will add that the sapphire gem has been picked on a lot. All of them have been picked on but especially the sapphire, since she’s one of my family member’s favorite chickens and one of my Orpingtons seems envious over that.
Two of my ~4 month old pullets have two types of marks on their faces. One was sold as a Sapphire Gem at Rural King (with a sign showing a light and dark color variation), the other was sold as a barred rock but I think she’s a black Australorp.
Marks
1): Black patches on the face and comb, as...