Hi Im not sure about this fork. I also have two spoons, of the same but not sure if they’re sterling or plated.
As Keltum is a Dutch company, if the fork were silver (not necessarily sterling as 833 is also a Dutch standard) it would have Dutch hallmarks. So your fork is either electroplated or base metal. A lack of any indication of electroplating (normally a number showing the number of grams of silver used in plating a set) leads me to suspect that it is a base metal alloy such as nickel silver.
Thanks for your response. Does Nickle silver typically polish with silver polish just like real silver?
No, it’s a white metal alloy similar to pewter.