Guide to Gold Jewelry Stamps and Inscriptions

Photo via Gold.Org

 

Most authentic gold jewelry is stamped with information about the purity level of the metal content. Generally, the stamp is placed in an inconspicuous place on the item so it does not detract from the design. Stamps are usually located on the inside of the band of the ring, on the post or basket setting on a pair of earrings, on the bail on a pendant, and on the connecting ring or the clasp on the necklace or bracelet.

The term karatage simply refers to the proportion of pure gold in a piece of jewellery. Karatage can be defined in two ways:

• as ‘fineness’ which expresses the amount of gold in parts out of 1000;
• as a ‘percentage’ of pure gold 

The first thing you need is a magnifying glass or a jeweler's loupe--a 30 x 21 mm which is what I use.  The table below lists the most common precious metal stamps on gold jewelry, their alternative stamps or hallmarks, their purity level, and alloys commonly used.

Metal stamp	Minimum percentage of pure gold	Common alloys**
10k Also: 416, 417, 10KP*	41.6% pure gold (10 parts out of 24) -minimum standard for U.S. gold	Usually silver, copper, zinc, and nickel
14k Also: 583, 585, 14KP*	58.3% pure gold (14 parts out of 24) -one of the most popular gold purities	Usually silver, copper, zinc, and nickel
18k Also: 750, 18KP*	75% pure gold (18 parts out of 24) -Standard international karatage	Usually silver, copper, nickel, and palladium (for white gold)
22k Also: 916, 917*	91.6% pure gold (22 parts out of 24) -popular in India and Middle East	Usually silver and copper
24k Also: 999*	100% pure gold (24 parts out of 24)	None

*Alternate stamp or European hallmark is a simple, three digit number representing the quality or fineness of Gold.

Additional Information

• Common alloys vary depending on desired color, such as white gold or rose gold
• The term "karat" (usually abbreviated as "k," "K," or "Kt") refers to the relative purity of gold; pure gold is 24 karats. "Karat" is different from "carat," which is a metric unit of weight for gemstones.
• In gold jewelry, "plumb" is an old-fashioned term that means that the fineness or purity level of the gold content is precisely what is stamped on the item. The word "Plumb" or the letter P still sometimes follows the metal stamp (e.g., "14k Plumb," "14KP").
  
• Other gold stampings such as 15kt, and 16kt gold are not used any longer. When a 15kt stamp appears in jewelry,  this would indicate it is a antique piece. Most 16kt gold is used for dental purposes only and you will not see it used in jewelry. Most of the other stampings 8kt, 9kt and 12kt are of a lesser gold quality and are not generally highly desirable.  

Does Gold Jewelry Have to Be Stamped? -- powered by ehow

Anything with one of these stamps below is not gold. It is made out of a different metal with a very thin gold layer that will wear off over time. These pieces do not have any real metal value and most gold buyers won’t purchase them from you except for sterling silver. Here are a few stamps which signify the piece is NOT gold:

• 14K 1/20 (1/20 gold is basically gold-filled)
• 14K G.F. (gold-filled)
• 14K G.P. (gold-plated)
• 14K H.G.E. (hydrostatic gold electroplating)
• 14K G.E.P. (gold electroplating)
• .925 (sterling silver)

So take note that even if your piece is stamped “14K” you cannot be 100% sure it is gold. There are a number of fake stamps out there and the only way to be 100% sure is to test the metal with a gold tester using nitric acid. On the other hand, even if there is no stamp it could still be gold.

Aside from the stamps or lack thereof, there are a couple other ways you (or most likely a jeweler) will be able to tell if the piece is gold like the nitric acid test or density test.

Related Post: How Can I Tell If Gold is Real?