My theory is Roman Provincial Sarapis wearing Kalathos reverse. It's smaller than what's listed on numista and Zeno has some similar ones. My scale stopped functioning so I can't get an approximate weight. Not more than 5 grams best guess. 18 x 16mm. 2.5mm thick. Has some good lettering on the reverse with a C just left of the Kalathos. Obverse is badly worn and has the appearance of one of the Roman emperors.