Are “18k Gold GP” and “18k Gold GF” real gold?
While their names are made purposely similar to 18k Gold, but the short answer is, No, any piece of product, even with some carefully chosen words to confuse customers such as "solid", if its name contains GP (gold-plated) or GF (gold-filled), it should not be considered as gold jewelry.
According to 《US Electronic Code of Federal Regulations Part 23 - Guides for the Jewelry, Precious Metals, and Pewter Industries》:
“..gold layer part of a gold-filled product must constitute at least 5% of the total weight of the item..”
So there is 5% gold content in gold filled (GF) products, and for the less-regulated gold plated (GP) products could vary anywhere from 0.25% to 1% of gold content. It is like a bottle of apple drink with only 5% of apple juice content is not REAL apple juice, right?
Then, what are 18k Gold GP and 18K Gold GF?
GP refers to gold-plated, means to cover another type of metal with a very thin layer of pure gold on top by using electroplating. Whereas GF is gold-filled, which has a thin layer of gold bonded to another metal by using mechanical method.
GP and GF jewelries are widely available nowadays because of their low price, and looks similar to their more expensive 18k Gold siblings at a glance, but they are not without drawbacks.
What are the differences between GP, GF and gold jewelries?
Durability - gold jewelry can virtually last forever, some cleaning can keep it as new for a long long time, and they are also serviceable. For GP and GF products, scratch and wear can damage its surface permanently, even without external force, the underlying metal will diffuse into the gold layer, causing gradual fading of its color and eventually tarnishing of the surface, and these are not repairable.
Value - gold jewelry value remains with the value of gold, this does not apply to GP and GF products.
Redesign/remodel - for gold jewelries, it is possible to reuse the gold and gemstones to make a new piece - where the gold and gemstones can be reused and thus substantially lower the cost of a new piece. This is not applicable for GP and GF products.
Allergy - it is quite common to be allergic to GP and GF products, who may develop itching, redness, rash problem where skin direct contact with the product. In comparison, it is very rare to be allergic to 14k or 18k gold.