I have this for some years now and hope someone can tell me more about it. I bought it in Northern Germany, so likely it comes from there. I think it is a fragment of a round window glass, and at its longest side it measures 9.5 cm. The glass itself has a lightly green colour which can not be seen on the photo. The painting is on the obverse side, only the grayish blue colour of the angel's wings is applied on the reverse. Can anyone tell me more about this and how old it is?