The word gold, used by itself, means all gold or 24 karat (24K) gold. Because 24K gold is soft, it's usually mixed with other metals to increaseits hardness and durability. If a piece of jewelry is not 24 karat gold, the karat quality should accompany any claim that the item is gold.
The karat quality marking tells you what proportion of gold is mixed withthe other metals. Fourteen karat (14K) jewelry contains 14 parts of gold,mixed in throughout with 10 parts of base metal. The higher the karat rating,the higher the proportion of gold in the piece of jewelry.
Most jewelry is marked with its karat quality, although marking is not required by law. Near the karat quality mark, you should see the name orthe U.S. registered trademark of the company that will stand behind themark. The trademark may be in the form of a name, symbol or initials. Ifyou don't see a trademark accompanying a quality mark on a piece of jewelry,look for another piece.
Solid gold refers to an item made of any karat gold, if the inside of theitem is not hollow. The proportion of gold in the piece of jewelry still isdetermined by the karat mark.
Jewelry can be plated with gold in a variety of ways. Gold plate refers toitems that are either mechanically plated, electroplated, or plated by anyother means with gold to a base metal. Eventually, gold plating wears away,but how soon will depend on how often the item is worn and how thick theplating is.
Gold-filled, gold overlay and rolled gold plate are terms used to describejewelry that has a layer of at least 10 karat gold mechanically bonded toa base metal. If the jewelry is marked with one of these terms, the term orabbreviation should follow the karat quality of the gold used (for example, 14K Gold Overlay or 12K RGP). If the layer of karat gold is less than 1/20th of the total weight of the item, any marking must state the actual percentageof karat gold, such as 1/40 14K Gold Overlay.
Gold electroplate describes jewelry that has a layer (at least .175 microns thick) of a minimum of 10 karat gold deposited on a base metal by an electrolytic process. The terms gold flashed or gold washed describe productsthat have an extremely thin electroplating of gold (less than .175 micronsthick). This will wear away more quickly than gold plate, gold-filled orgold electroplate.