The carat: the unit of measurement for gold
The carat is an essential concept in the world of jewelry and gemology. It defines the purity of gold and other precious metals, thus influencing the quality and value of jewelry. But what exactly is a carat? How is it calculated and what is its impact on the price and durability of gold jewelry? In this article, we explain everything you need to know about the carat, its origin and its influence in the world of jewelry.
The origins of the carat
To understand the principle of the carat, we must go back to the etymological origins of the word. The "Quirat" was an old maritime term. A ship was once divided into 24 equal parts, and each owner owned a number of shares expressed in "quirat".
History also remembers the words "quarais" and "caraz", derived from the Italian "carato", itself descended from the Latin "caratus" and the Arabic "qīrāṭ", which referred to the carob seed used as a unit of weight in Mecca. This term also has its roots in the ancient Greek "κεράτιον" (keration), referring to the carob, used as a standard measure.
What is a carat?
Definition of the carat
The carat ("ct" or "K" in English) is the unit of measure that determines the purity of gold. It corresponds to the proportion of gold present in a metallic alloy. Pure gold is defined as being 24 carats (24K), or 99.9% gold.
Why is gold alloyed with other metals?
Pure gold (24K) is too malleable to be used in the manufacture of jewelry worn daily. To improve its resistance, it is mixed with other metals such as silver, copper or palladium. The caratage of gold thus indicates the proportion of gold in the alloy.
The carat or the degree of purity of gold
In jewelry, the carat is a unit of measure used to express the purity of a precious metal. Cut into 24 equal parts, each carat represents just under 4.17% of a whole. Note that the carat is also used in gemology as a unit of weight, where 5 carats correspond to 1 gram.
The main caratages of gold
24 carat gold: pure gold
24 carat gold is composed of 99.99% gold. Created mainly by major jewelry houses, 24 carat gold jewelry is rare and expensive due to its purity. However, this gold is extremely malleable, which limits its use in traditional jewelry.
22 carat gold
22 carat gold contains 91.6% pure gold. It is mainly used in the Middle East and Asia for wedding jewelry. Less malleable than 24K, it is still too soft for jewelry set with precious stones.
18 carat gold: the standard in jewelry
18 carat gold contains 75% pure gold and is the most used in luxury jewelry. It allows for alloys such as white gold or rose gold, and offers a perfect balance between purity, aesthetics and resistance.
14 carat gold
With 58.5% pure gold, 14 carat gold is more affordable and more resistant than 18K gold. It is ideal for everyday jewelry.
9 carat gold: an economical alternative
The 9K gold contains 37.5% pure gold and 62.5% other metals. It is often compared to gold-plated, but unlike the latter, it is solid. It is more affordable but has a lower market value for resale.
Table of carat titration
| Carat Rating | Gold Percentage |
| 24K | 999,9 ‰ |
| 22K | 916 ‰ |
| 19K | 800 ‰ |
| 18K | 752 ‰ |
| 14K | 585 ‰ |
| 12K | 500 ‰ |
| 10K | 417 ‰ |
| 9K | 375 ‰ |
| 8K | 333 ‰ |
Table of carat titration
| Carat Rating | Gold Percentage |
| 24K | 999,9 ‰ |
| 22K | 916 ‰ |
| 19K | 800 ‰ |
| 18K | 752 ‰ |
| 14K | 585 ‰ |
| 12K | 500 ‰ |
| 10K | 417 ‰ |
| 9K | 375 ‰ |
| 8K | 333 ‰ |
Gold Alloys and Their Colors
Pure gold (24 carats) is naturally intense yellow, but it can be modified by adding other metals to change its color and durability. Here are the main gold alloys:
- Yellow Gold: Composed of gold, silver, and copper. This is the traditional color of gold and one of the most popular in jewelry.
- White Gold: Alloy of gold and palladium or nickel, covered with a thin layer of rhodium to enhance its whiteness and shine.
- Rose Gold: Obtained by mixing gold with a larger proportion of copper, giving it a warm and trendy hue.
- Gray Gold: Contains gold, copper, and palladium. Unlike white gold, it is not rhodium-plated.
Each type of alloy has its own advantages in terms of resistance and aesthetics. The choice of color for a gold piece of jewelry depends on personal tastes and the desired style.
How to recognize the carat of a gold piece of jewelry?
With the naked eye
The color of pure gold is very bright. The more an alloy is diluted with other metals, the more its hue is attenuated.
Guarantee stamps
Each gold piece of jewelry has a stamp attesting to its titration. Here are the most common ones:
Seahorse: 24 carat gold
Eagle's head: 18 carat gold
Scallop shell: 14 carat gold
Clover: 9 carat gold
Verification tests
- Acid test: Allows estimating the purity of gold.
- Touchstone test: Chemical analysis by abrasion.
- X-ray spectrometry: Precise analysis without degrading the jewelry.
- Electronic test: Use of a specific device to determine the caratage.
Impact of carat on the value and price of gold
Gold price depending on the carat
The price of gold varies depending on its caratage and the price of gold on the market. 24K gold is the most expensive, followed by other alloys according to their content of pure gold.
Carat and investment
24K gold is often preferred for bullion and investment, while 18K and 22K gold are ideal for high-end jewelry.
Why are jewelry not made of pure gold?
Pure gold is too malleable and easily damaged. To overcome this problem, alloys with other metals (silver, copper, zinc) are created. This improves durability and allows for varying shades.
How to choose the right carat for a piece of jewelry?
- Everyday jewelry: 14K or 18K gold is recommended for their durability.
- Exceptional pieces: 22K or 24K gold is ideal for collectible jewelry.
- Investment: Opt for 24K gold in the form of ingots or coins.
Maintenance and preservation of gold jewelry
The maintenance of gold jewelry varies according to their carat. The purer the gold, the more malleable and sensitive to scratches it is. Here are some general tips to preserve their shine and durability:
- Avoid shocks and scratches: Pure gold (24K and 22K) being softer, it is preferable not to wear it during physical activities.
- Clean regularly: Use a soft cloth and warm soapy water to remove impurities. Avoid abrasive products.
- Store your jewelry properly: Keep them in a velvet-lined case or in separate pouches to avoid friction.
- Rhodium plate your white gold jewelry: To maintain their shine, a rhodium treatment every 2-3 years is recommended.
- Protect 9K gold: It can oxidize more quickly, so it is advisable to maintain it with a specific polishing cloth.
By following these precautions, you will prolong the beauty and longevity of your gold jewelry.
Conclusion
The carat is an essential element in determining the quality and value of a gold piece of jewelry. Choosing the right carat allows you to adapt your purchase to your needs, whether for daily use or for an investment. At Celinni, we offer a selection of high-quality gold jewelry, suitable for all requirements.
FAQ - Frequently Asked Questions about Gold Carat
- What is the carat in gold?
The carat is the unit of measure that determines the purity of gold. It is expressed in 24 parts, pure gold being 24 carats (24K). - What is the difference between 24 carat gold and 18 carat gold?
24 carat gold is 99.9% pure, while 18 carat gold contains 75% pure gold and 25% other metals to improve its resistance. - How to recognize the carat of a gold piece of jewelry?
There are several ways: official hallmarks engraved on the jewelry, acid chemical tests, and X-ray spectrometry analyses carried out by professionals. - Where to buy your gold jewelry?
In order to offer all our customers the most beautiful gold jewelry, Celinni has selected the best high-end models. Whether you are looking for a ring, a necklace or a gold bracelet, you are sure to find the jewelry that meets all your desires and at the best price on our online jewelry store. - How to maintain your gold jewelry?
- 24K and 22K Gold: Clean with a soft cloth and store away from shocks.
- 18K and 14K Gold: Regular cleaning with warm soapy water.
- 9K Gold: Protect from moisture and use a polishing cloth.
