silver ring or platinum?

by emma
(lincoln)

i was given this ring and i am not sure what it is made of - i was told it was made from platinum, but i am not sure as the marks don't make sense, it does not have any lion mark on it at all. on one side it has an arrow shaped mark, that is how best i can describe it and on the other side it has i F mark but can't make out the other it looks like an a or an e could you tell me if this ring is worth insurance it also has a quarter diamond. sorry don't have any pictures