The large of the pair, and also one with an attempt at a background, is a mix of the mark that appears over Rachel Grey's eye when she uses her powers and the tattoo that was branded onto her back at some point when she was being hunted down for being the Phoenix.
The smaller one is one of my eraser stamps of the same mark over her eye. It's head looks disconnected because the original pencil I picked up to use was a color pencil and not lead/graphite pencil and thus it didn't leave any lines on the surface. Ah well. I'll know for next time.