After extensive digging, I found this on a German website (http://www.emuenzen.de). It might fit your medal.
S.GEORGIUS EQUTUM PATRONUS means St. George Patron of the Knight. (Is this on the other side: IN TEMPERE SECURITAS?) One was found in a field in northern Germany. This is a St. George medal, which was very likely struck, as a talisman/bringer of luck, in about 1772. Made in large quantities, at first in silver, later mostly of copper or bronze (often silvered), and mostly with a hanging loop or eye. The motto has not changed much over the centuries, because they were repeatedly copied. Because of this, the year and place of production are difficult to trace. Value: even in good condition, they can still be found at the bottom of odds-and-ends/remnants boxes at fleamarkets.
One was recently sold on ebay for about $6.99.