Markings on Gold Jewelry
One thing I used to learn when I worked for an auction gallery in San Francisco was that we should never claim to be selling gold, when we were not. For example, a bracelet that looked like gold, but did not have a special marking indicating that it really was, could be called only gold colored metal in the catalog, so as not to mislead the buyers. Many people want to know what the markings actually mean on gold jewelry that they have in the family, or that they see in shops. Wedding rings, necklaces, bracelets, earrings and other gold jewelry will tell how pure the gold is, usually by signifying marks like 18K or 14K; even though the word carat does not begin with a K, we use that abbreviation. Also it is possible to have a 3-digit number indicating the percentage of gold. The number is like a major league baseball player's batting average, in that we must interpolate an imaginary decimal point as being in front of the number. Therefore, the number 926 is really 0.926; that decimal number translates to 92.6% pure gold. Here are some of the examples of gold qualities: a 9 carat gold ring might bear the stamp 9K or perhaps 375, meaning 37.5% gold, which by definition means 9 carat gold. Such a low grade would be hard and brittle usually, being comprised mainly of cheaper metals, called alloys, mixed in with the softer gold. A slightly more valuable gold would be 10 carats, meaning that it is more pure gold than a 9K., and less a mixture of non-valuable metals than the 9K. The 10 carat gold could bear a stamp 10K, 10ct, 10Kt (all meaning ten carat) or else a stamp reading 417, meaning 41.7% gold (that percentage being the definition of a 10-carat quality gold). Next, 12-carat is 50% gold. Coming up the ladder, 58.5% is a 14-carat concentration of gold; and a 75% purity would make it 18-carat gold, which is about as good as we usually see in our American jewelry. Other countries around the world have topped us however, at least in the field of gold purity, and often produce jewelry of 22 and 24 carat gold quality. The max would be the 24K at 99.95% gold (why not call it pure gold). Now, let's take an example. Say you have a ring bearing the mark 926, which perhaps came from another country. This is pretty close to pure gold, in fact it would indicate the ring is 92.6% gold. The standard 22K is set at exactly 91.7%. Your ring honestly could be called slightly more than 22K. If it feels nice and soft, it is probably the real thing, close to pure gold, but of course everything has to be appraised professionally, if you want to advertise and sell. A friendly jeweler might give you a good honest answer as to whether your interpretation of the markings on any of your jewelry is accurate. I hope this has helped with a few things you might not have known before.
The Purpose of the Markings
You, as a buyer, are the primary purpose of the markings on precious metal jewelry. The legalities of high priced purchases require sellers to be as honest as possible with their customers.
One style of marking may replace another depending on the location where the jewelry originally was manufactured. It's just a matter of keeping consistent with the type of markings used in that location traditionally. Europe, for example, likes to denote the purity of their gold by using the decimal system, while America prefers the carat marking.
Usually you can feel when a precious metal is close to being pure. It generally has a very soft feel. This is true of both gold and silver. But the markings are the final deciding factor, not the feel.
Really pure metals, however, can be bent and damaged easily. This is why a little bit of a stronger metal (an alloy) usually is mixed with the precious metal.
Gold may have a variety of different shades and colors. This comes from the differences between the various alloys mixed with the gold.
Some of the cheaper jewelry you will find isn't gold all the way through. It's really plated with just a thin layer of gold on top of a non-precious metal underneath. When the thin top layer wears off, the cheap metal underneath is revealed. These electroplated pieces of jewelry often are marked with the initials HGE (heavy gold electroplate).
When the electroplating process is more generous with the amount of gold used, jewelers like to use the expression "gold filled." It's still gold plated, but the plate is a little thicker. A more extensive marking may appear on such jewelry. For example, 1/30 14K GF, means that gold comprises only 1/30th of the total weight of the metal, and is of a purity of 14 carats. The GF denotes gold filled.