| INFORMATION FOR GOLD ESTATE JEWELRY
Gold is the most malleable and durable of metals. It does not tarnish.
Pure Gold is virtually immune to the effects of air, water and oxygen.
Every country has a different system for hallmarking gold.
In the United States, the purity of gold is designated by karat. Pure gold is 24K, but 24K is rarely used to make jewelry because pure gold will not hold gemstones and bends too easily. Other metals such as copper, silver, zinc and nickel are added to gold to improve strength and durability. Metal additives will determine the color and karat of gold. Vintage gold rings marked with "KP" would indicate that the gold is "Karat Plumb" or a true 14KT. This is based on gold regulations passed in 1978 that gold may only vary within 1/2 of a karat to qualify for a KT marking.
In Europe, gold is stamped according to its fineness. Pure gold is stamped 1000 fine. 18K is 75 percent or 750 fine. So, an 18K ring made in Europe would be stamped 750.
In England, estate jewelry may be marked "ct" for karat with a "c" instead of a "k", this hallmark was used form 1789 to 1975.
It is not correct to measure the purity of gold used in estate jewelry, antique jewelry or vintage jewelry solely based on a gold hallmark. Many pieces of estate jewelry were never hallmarked and some gold jewelry hallmarks may have worn off with wear and use. Often gold marks were inaccurate.
COMMON GOLD HALLMARKS FOR FINE ESTATE JEWELRY AND CONTEMPORARY VINTAGE JEWELRY
| US Karats |
Percent of Gold |
Fineness |
| 24 |
100% |
1000 |
| 22 |
95.83% |
958 |
| 18 |
75% |
750 |
| 15 |
62.50% |
625 |
| 14 |
58.33% |
583 |
| 10 |
41.67% |
417 |
| 9 |
37.50% |
375 |
GOLD COLORS IN ESTATE JEWELRY
Two factors determine gold color. One is the alloy used to mix with the gold and the other is the percentage of the alloys used.
Yellow Gold
Yellow Gold is the natural gold color. Pure gold mixed with silver and copper to retain the bright gold color.
Bright Yellow Gold
Pure gold mixed with copper, nickel and zinc.
White Gold
Pure gold is mixed with a large percentage of silver, along with nickel and zinc to get the white color. 18K White gold has a slightly yellowish color if not enough silver is added. In order to get a shinny white color sometimes estate white gold rings have been plated with rhodium. During the 1920s and the 1930s, white gold became very attractive to compete with platinum jewelry. Many estate engagement rings and antique filigree engagement rings of that period were made with 14kt or 18kt white gold.
Rose Gold or Pink Gold
Pure Gold mixed with large percentage of copper in addition to silver and zinc to get the rose color. Estate rings made with rose gold or pink gold were made frequently in the "Retro Modern Jewelry Period." These period jewelry pieces are gaining new popularity.
Deep Green
Pure gold mixed with fine silver, copper and zinc. Green gold, and often gold made of three colors may be an indication that an estate jewelry piece may again be "retro modern jewelry".
Bright Red
Pure gold mixed with a higher percentage of copper.
Rolled Gold Plate
Jewelry marked 14K R.G.P. is not 14 karat gold. The R.G.P. stands for "rolled gold plate", which is applying a layer of gold alloy to a layer of base metal. Antique rings, necklaces, and pins made of rolled gold plating were very popular in the 1800s and 1900s. This type of antique jewelry may also be marked "rolled gold plate."
Gold Electroplating
Jewelry marked 14K H.G.E. has been gold plated or "hard gold electroplated". Meaning the piece of base metal has been plated with a thin coating of gold by an electrical process.
Gold-Filled
Jewelry marked with 14K G.F. indicates that the jewelry is "gold-filled". The jewelry is not "gold-filled", but is made by joining a layer of gold to a base metal as in rolled gold plating. There is more gold in gold-filled than in rolled gold plating.
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