Read the stamp
What does GP mean on jewelry
18K GP describes plating made with an 18-karat gold alloy. GP means gold plated: a gold surface layer over another metal.
Reading GP after a karat figure
18K GP describes plating made with an 18-karat gold alloy. The 18K value belongs to that layer. GP alone supplies no thickness or gold-weight fraction. GOLD PLATED is the spelled-out form.
What to check next
Compare GF and RGP, which describe mechanically applied layers, with GP and HGE, which describe plating. Look at the entire coating stamp before interpreting a karat number. At worn edges the base metal may be visible; a maker signature beside the construction mark identifies the company.
Related marks
4 marks
