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Although we buy mostly for an item's beauty, this is one of the most important questions asked about old jewelry. The metal not only plays a major role in determining value but can also provide clues as to when and where the piece was made.

GOLD

In the United States the purity is designated by Karat. Pure gold is 24k, but, because of its softness, it is not suitable for making jewelry. Other metals such as copper, silver, nickel, and zinc are added to gold to strengthen it. Which metals and how much of each is added determine the color and the Karat of the gold.

To make this easier to understand let's take an imaginary ring and examine it. The color of the metal is immediately apparent. Gold comes in several colors, but let's pretend that this ring is pink gold. The inside of the ring is stamped 10K. What do these things tell us? First, that the gold was mixed with copper, silver, and zinc to make yellow gold. The pink look was achieved by using a larger quantity of copper. The 10k mark represents that 41.67% of the metal is pure gold, and the other 58.33% is copper, silver, and zinc. It also indicates that the piece was made in the United States. (Other countries do not use 10k.) A 14k stamping would mean that the ring contained 58.33% gold and 41.67% other metals. If the ring was marked 18k, it would contain 75% pure gold and 25% other metals.

In Europe gold is stamped according to its fineness. Pure gold is 1000 fine; 18k gold is 75% or 750 fine. Consequently, an 18k ring made in Europe would be stamped 750.

Below is a chart of the most common Karat markings.

ROLLED GOLD PLATE

Always be sure to look for other letters that might be stamped next to the karat sign. A piece marked 14k R.G.P. is not 14 Karat gold. The R.G.P. stands for rolled gold plate, which is made by applying a layer of gold alloy to a layer of base metal. This "sandwich" is then drawn to the thickness needed for the piece of jewelry. Rolled gold plating was very popular in the 1800's and early 1900's.

GOLD FILLED

Other letters that sometimes appear next to the Karat number are G.F. This signifies the piece is gold filled. The name is misleading because the piece is not filled with gold as the name implies, but is made by joining a layer of gold to a base metal as in rolled gold plating. The layer of gold used in gold filled is thicker than the one used in R.G.P., making it more durable.

ELECTROPLATING

If the piece in question is marked 14k H.G.E., it has been gold plated. The initials stand for Hard Gold Electroplated. It means that the piece is made of base metal that has been plated with a thin coating of gold by an electrical process.