"An etching found on the wall of an old missionary in Southern California. There was a bricked over doorway next to it. What is this thing?"
A: "I did a little digging on the rhombus symbology. I believe it’s also called a lozenge. “A lozenge shaped escutcheon is used to depict heraldry for a female (in continental Europe especially an unmarried woman), but is also sometimes used as a shape for mural monuments in churches which commemorate females”"