When buying a piece of gold jewelry - especially if it is bought second hand (auction, tag sales, classifieds) - it is important to be aware of the content of gold in the piece to determine its value. True gold jewelry is much more valuable than jewelry that is plated gold. Here are some common markings found on gold:
24k, 22k, 18k, 14k, 12k, 9k - All of these refer to the amount of gold in the metal alloy used in the jewelry. 24K is pure gold and the lower the number the less the gold content.
.750 - The same as 18K. It means the metal alloy is 75% gold, just as 18K means the alloy is 18 out of 24 parts gold (18/24 or 75%)
.585 - The same as 14K, 58.5% gold.
If used alone, any of the marks above mean the piece is solid gold. If used together with any gold filled or gold plating marks, then this means only the gold plating is the alloy mentioned and it is covering a base (not valuable) metal.
Gold Plate, Gold Filled, G.P., G.F., Rolled Gold, 1/20 - All of these mean the piece is Plated and the different terms refer to the thickness of the gold plating.
