If an item is marked/stamped as "1/20 12k GF", it means that the gold layer is 12 karat gold and comprises 1/20th of the total weight of the item.
Gold Filled (GF) is a thin sheet of karat gold (10K, 12K and 14K) which is fused to a thicker sheet made out of base metals of different alloys such as brāss/bronze. Sterling Silver is also used, though less common. The process usually involves rolling the two sheets together to a desired thickness (hence the synonym: Rolled gold).
Check out how to calculate its scrap value at Goldnscrap.com.
Although it is lower in gold content, gold filled jewelry has many advantages. It is stronger than karat gold jewelry because the inner core of base metal adds structural strength. It is extremely durable because the gold plating is so thick. Unlike rolled gold or gold electroplate, it is rare to see gold filled jewelry which has lost its gold surface.
Solid gold jewellery is a purchase that you will be able to enjoy for life, even generations, so before you make a purchase it is wise to educate yourself on the different standards of gold available. Check out some key facts about gold before making a jewellery purchase and what to look out for as a shopper at Edgeonly.com.