Found this very deep at an old site where some dirt was turned over. It's crusty but seems like a button appears to be a cross on back and 4 dimples on front or not sure if that is just deterioration of button. Any thoughts?
NOLA_Ken answered before I saw your post. He is right... it is an iron stamped-sheetmetal 4-hole (a.k.a. "long-underwear/undershirt") button, whose holes are crusted-over by rust, which gives the appearance of being dimples around a cross. That type of button has been manufactured continuously ever since the early-1800s (perhaps earlier), and is still being made today. There's no way to time-date one unless it has a maker's-mark or an identifiable "patented" form.