What does 1/20 12 kgf mean on gold necklace

An item marked as "1/20 12k GF" would mean that 1/20th of its total weight must be 12 karat gold. The surface layer of karat gold is usually 10kt, 12kt, or 14kt
Updated on Monday, February 06 2012 at 03:16AM EST
Collection: surface layer