I think this is a badge (13.5 x 9.5cm) off an undress sabretache, ie plain leather, possibly at the time of Johann, King of Saxony (hence JR), 1854-73. It may be an unfinished piece, inasmuch as there are no fixing points on the reverse. It would appear to be a cast bronze, hand finished badge.

This impressed silver cross (5cm square) would have been worn in the 19th century, anywhere from Waterloo through to the Franco-Prussian war of 1871. It would probably have been worn on the soft field cap or shako. It doesn't have the usual logo of Mit Gott etc. However, it is almost certainly a Prussian example on account the Maltese cross design.