The stamp on this piece of gold could indicate its intended use and how many, if any, other metals were added to it. Many of us at one point or another will sell gold we bought from a department store or jewelry store. If you’ve ever gone shopping for jewelry, you have probably heard the word “karat” applied to gold. The higher the karat, the more expensive it will be. But have you ever wondered why? The short answer is that higher karats mean more gold, but there is more to it than that.
What Are Karats?
Karats are the little numbers stamped on a piece of gold in the format of “xxK” or “xxKT.” The numbers refer to the type of gold and to the actual gold content in the particular piece of jewelry.
Here’s more information on karats:
- A karat is a measurement of the ratio of gold to other metals or alloys.
- Karats are measured on a scale from 0 to 24.
- A higher karat number means the piece contains more gold and less other metal content.
- Other metals and alloys could include copper, nickel, silver, or palladium.
24-karat gold is the purest gold you can buy. Gold is malleable in its pure state, so other metals are added to strengthen it and in some cases to enhance color.
How to Use Karats to Measure Gold Purity
Here is how to use the number of karats to figure out how pure your gold is: If you purchase a ring that is 14K gold, since the highest amount of karats you can have is 24K, divide the 14 karats by the 24. You will get .583. This means that the gold is 58.3% pure in a perfect world. In reality, jewelry gold purity can vary 10 to 20% (usually toward the lower end).
Gold Purity Terminology
- Assay: A test which determines metal content and quality.
- Bullion: Precious metals in bulk, uncoined form, such as gold bars, considered in mass rather than value.
- Carat: Not to be confused with karat, a carat is a unit of measurement used for precious stones.
- Ductile/Ductility: How susceptible a metal is to being deformed by using tensile force. Ex. Ductile materials can be stretched into thin wires without fracture.
- Hallmark: A symbol or mark stamped on a piece of precious metal which certifies its standard of purity.
- Karat: Unit of measurement for the fineness of gold, with the higher numbers indicating higher gold content and 24K being the finest.
- Malleable/Malleability: How susceptible a metal is of being deformed by using compressive force. Ex. Malleable metals can be hammered or rolled into thin sheets.
- Millesimal Fineness: A system used to show the purity of precious metals by parts per thousand rather than karats.
- Troy Ounce: 31.1034768 grams, or approximately 1.09714 standard “avoirdupois” ounces.
- Troy Weight: A system of measurement used for gemstones and precious metals, where a full Troy Pound consists of 12 “troy” ounces rather than the 16 “avoirdupois” ounces in a standard pound.
What Do the Stamps on Gold Mean?
Here’s a list of stamps you might find on a piece of gold and what they mean.
375: This means the gold is 37.5% pure, or 9K.
417: This means the gold is 41.7% pure, or 10K.
585: This means the gold is 58.5% pure, or 14K.
667: This means the gold is 66.7% pure, or 16K.
Not commonly used in jewelry, but often seen in dental gold, which is alloyed for strength.
750: This means the gold is 75.0% pure, or 18K.
916: This means the gold is 91.6% pure, or 22K.
999: This means the gold is 99.9% pure, or 24K.
Here are some common stamps found on items that are not gold, and what they mean:
EPNS: Stands for Electroplated Nickel Silver. This is a base-metal item with a thin plated surface. It is not gold.
EPBM: Stands for Electroplated Britannia Metal. Another base-metal alloy that may be plated, but is not gold.
GE: Stands for Gold Electroplate. A thin layer of gold applied over a base metal. It is not solid gold.
HGE: Stands for Heavy Gold Electroplate. Similar to GE, but with a thicker layer of gold. Still not solid gold.
GF: Stands for Gold Filled. A layer of gold bonded to a base metal. Contains more gold than plating, but is not solid gold.
We also purchase a wide range of related items — you can see a full list on our What We Buy page.