 The Lord Baltimore penny copper coin was similar to the silver coins with the main difference being the back side.The reverse side of the copper penny is a duke's coronet crown with two pennons flying in the center and the writing around this image of "Denarium Terrae-Mariae" ("Denarius of Mary’s land").The diameter is about 13/16th of an inch, which is a size between that of the Lord Baltimore groat and sixpence coins, and it weighs 57.5 grains.