When shopping for gold jewelry, you might find yourself wondering what "14K gold" means. How is it different from 18K gold? Why is one more expensive? Is 10K gold real gold?
The K stands for "karat". Gold purity is measured in karats. The karat purity of a piece of jewelry tells you what percentage of the jewelry is pure gold.
24 karat is 100% pure gold. Pure gold is very soft and is not practical for use in jewelry, as it scratches, bends, and dents very easily. Gold used in jewelry is mixed with alloy metals like silver, copper, nickel, and zinc to give it more strength and durability. Fine gold jewelry is usually between 10K and 22K.
|Gold Purity Chart|
|Number of Karats||Parts of Gold||% of Gold Purity||Millesimal Fineness|
|24 karat||24/24 parts gold||100% gold||999|
|22 karat||22/24 parts gold||91.7% gold||916/917|
|18 karat||18/24 parts gold||75.0% gold||750|
|14 karat||14/24 parts gold||58.3% gold||583/585|
|10 karat||10/24 parts gold||41.7% gold||416/417|
Advantages of Lower Purity and Higher Purity Gold Jewelry
Pure gold is a deep and bright yellow-orange color. It's very uncommon to see pure 24K gold in wearable jewelry. It's blended with different metal alloys to create the yellow, rose, and white gold you're used to seeing in jewelry.
When shopping for gold jewelry, choose the metal purity that makes the most sense for the type of jewelry you are buying. Also consider the wearer's skin sensitivity, activity level, and their personal taste. Last, but not least, the budget will play a part in your gold purity choice.
The higher the percentage of pure gold content, the lower the risk of skin irritation for those with nickel allergies. The color of higher purity yellow and rose gold is richer and more intense than lower purity gold jewelry pieces. Higher purity gold is less durable, so it's not a good choice for every day wear especially for people who are very active or work with their hands. Higher purity gold jewelry will always cost more than lower purity gold jewelry of the same weight.
The lower the percentage of pure gold content, the more durable and appropriate for everyday wear. The color of lower purity gold can be paler and less rich than higher content gold purity pieces. The cost is also lower per gram weight than higher gold content jewelry pieces.
A happy medium is 14K gold. It provides the best combination of color, durability, and affordability. 14K gold jewelry makes up the vast majority of gold jewelry created and sold in the United States.
Jewelry Stamps or Hallmarks
When looking at a piece of fine jewelry, you may notice a stamp or engraving on the inside of a ring, the back of a pendant, or on an earring back or post. These jewelry stamps, or hallmarks, can tell you what metal purity makes up the piece of jewelry.
It's important to keep in mind that if a piece has been sized or has a lot of wear, the hallmark may have been removed (in the case of sizing a ring down) or may have worn away to the point of being illegible. Just because there is not a hallmark right now doesn't mean there wasn't one at some point. And some jewelers don't hallmark their pieces at all.
Jewelry Hallmark Meanings
- 925: Sterling silver
- 10K or 417: 10K gold
- 14K or 585: 14K gold
- 18K or 750: 18K gold
- 22K or 917: 22K gold
- PLAT: Platinum
- PD: Palladium
- GE: Gold electroplated
- GP: Gold plated
- GF: Gold filled
Testing Gold for Purity
If there's no hallmark, and the gold purity of the jewelry item is in question, there are ways for the jewelry professionals Oaks Jewelry to test and discover the metal purity to help determine the value of the piece.
First, a visual inspection can give many clues as to whether or not a piece of jewelry is real gold and what gold purity it may be. If there are any spots on the piece where the gold finish is rubbed away it could indicate a gold plated piece. The item's heft, color, and reflectivity are also good visual clues.
A simple method we use for determining gold purity in jewelry is the “touchstone” testing process, an age-old technique that is relatively nondestructive to jewelry and offers quick results. Touchstone testing is based on the fact that 24k gold resists all but the strongest acids. The purer the gold, the stronger the acid required to dissolve it.
The piece of jewelry to be tested is gently rubbed on the touchstone to leave a metal sample. Metal samples with known pieces of 10K through 24K gold purity are also deposited onto the stone. Various strengths of acid are then used to dissolve the metal samples. The higher the acid strength it takes to dissolve the metal, the higher the gold purity of the piece of jewelry.
Acid testing can also be carried out on a piece of jewelry itself after making a small scratch or notch in the metal. This is done somewhere on the piece that's not easily visible.
We may also use an electronic testing device that tests the conductive properties of the metal of the jewelry item.
Gold Purity Terminology
Let's look at a few terms that you may come across when studying about or shopping for gold:
- Assay: A test which determines metal content and quality
- Bullion: Precious metals in a bulk, uncoined form such as gold bars
- Ductile/Ductility: How capable a metal is to being deformed using tensile force. Ex. Ductile materials can be stretched into thin wires without fracture
- Gold filled: Gold filled jewelry is NOT gold jewelry. Gold filled jewelry is made by taking one or more sheets of solid gold (14K, 12K, 18K, etc) and wrapping them around a base metal under intense pressure.
- Gold Plated: Gold plated jewelry is NOT gold jewelry. Gold plated jewelry is jewelry made of a base metal (e.g. copper) or silver that has a very thin layer of gold applied to the top.
- 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 containing more gold and 24K being the finest
- Malleable/Malleability: How capable a metal is of being deformed 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 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 ounces in a standard pound