Do you have any idea what is in the picture? The course is made of silver. Sorry my English is not so good.
if it is a coin, and i would also guess it isn't...then i would guess it is a type of very thin medieval coin called a bracteate, i have one of the type... Bela III - Bela IV of Hungary, 1172-1270 AD, AR Bracteate Head right, reverse incuse of obverse. Unger 122. 16 mm, 0.4 g