Dug American or Continental Revolutionary War Navy coat button. The front has a crudely engraved vertical anchor surrounded by 13 "stars" & a border design. The stars are thirteen little engraved dashes. It is flat and looks to be bronze. The shank is missing. It was dug in a camp in Northern N.J. and was probably made in the field. It measures  22.5 mm in diameter. It will be mailed in the little lidded plastic button case you see in a few of pictures. The pictures show the details. If you have any questions just send me a message. Thanks, Jim D