Employs a process in which gold is bonded with heat and pressure to a base metal alloy such as nickel, rhodium, brass and sterling silver. Commonly, the amount of gold used must make up at least 5% of the total weight and all exterior portions are solid gold.
Most gold filled jewelry pieces tend to be 18K.
It does not flake off, rub off or turn colors. As a matter of fact, anyone who can wear gold can wear gold filled without worries of any allergic reaction to the jewelry.
Gold filled items are regulated by the U.S. government. These items are therefore so much better then gold plated which has no regulations at all. Caring for Gold Filled items is as easy as caring for any gold jewelry. Simply keep away from chemicals, clean regularly with mildly sudsy water, rinse well and pat dry with a non-scratching cloth. Polish gently with a jewelry polishing cloth.
Some high quality gold-filled pieces have the same appearance as 14 karat gold. In the USA the quality of gold filled is defined by the Federal Trade Commission. If the gold layer is 10 k fineness the minimum layer of karat gold in an item stamped GF must equal at least 1/10 the weight of the total item. If the gold layer is 12 k or higher the minimum layer of karat gold in an item stamped GF must equal at least 1/20 the weight of the total item. The most common stamps found on gold-filled jewelry are 1/20 12k GF and 1/20 14k GF. Also common is 1/10 10k.
Double clad, gold-filled sheet is produced with 1/2 the thickness of gold on each side. 1/20 14K double clad gold-filled has a layer on each side of 1/40th 14K making the total content of gold 1/20. The thinner layer on each side does not wear as well as single clad gold-filled.
TheFederal Trade Commission allows the use of Rolled Gold Plate or R.G.P. on items with lower thicknesses of gold than are required for gold filled.
A 12 k gold layer that is 1/40 the weight of the total item is designated as 1/40 12k RGP. This lower quality does not wear as well as gold-filled items.
Gold-filled items, even with daily wear, can last five to 30 years but will eventually wear through. The gold layer on gold-plated jewelry varies greatly depending on manufacturer, so there is no single, simple comparison. Gold-filled items are 50 to 100,000 times thicker than regular gold plating, and 17 to 25,000 times thicker than Heavy Gold Electroplate, sometimes stamped HGE or HGP—usually found on cubic circonia cocktail rings.
Mainly, there are three agreed mass ratios of which a sheet of gold would be considered as Gold Filled. Minimal karat should be of 10K.
1/5 – 10K , 12K , 14K
1/10 – 10K , 12K , 14K
1/20 – 10K , 12K , 14K
Any figure above 1/20 will not be considered as Gold filled as well, it is now called Rolled Gold Plate (R.G.P) or Heavy Gold Plate (HGE) and usually is marked that way.
The known gold to base metals ratios for R.G.P are: 1/40 and 1/50
Karat ranges from 10K to 18K
Gold filled cannot be cast.
It is a layered product with the gold comprising a surface layer. To cast an item the material used to make the casting must be melted to a molten state and the gold would become mixed throughout the product, so the finished item would no longer have the solid gold surface layer.
Difference between cast, die-cut and hand-made.
- Cast components are made from pouring molten metal into a mold to form the part. In ‘lost wax casting’ a wax model of the part is replaced by the molten metal.
- Die Cut components are stamped and formed in metal dies from metal sheet on a machine press.
- Hand-made components are made up by a skilled craftsman from basic metal sheet, wire and solder.
Value of gold filled.
The value of your gold jewelry depends on what kind of marking is on the piece. Gold filled means gold, filled with some other base metal. If the marking is 1/20 12k, and 100 g piece of jewelry, then you can be guaranteed that the weight of the gold in that piece is at least that fraction.
How much gold would be in a 100g piece of jewelry of 1/20 12K Gold filled? 1/20 = 0.05 (or 5%) 100g x 0.05 = 5g, 12K = 12/24 = 0.5 (or 50%), 5g x 0.5 = 2.5g, 2.5g of pure gold.
This is 0.081 troy ounces. Now, with gold crossing $1,230 per troy ounce recently, this would put the value of the gold in your piece of jewelry at 0.081 times $1,230, or $ 100.
A place that accepts gold will give you less than $100 for the jewel, since they need to make a profit on the transaction.
I will continue the explanations for each metal.
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