If you took a piece of golden jewelry and inspected it closely, you might have noticed a small engraving on it. Usually located somewhere on the edge of the item, or on the inner side of a piece of jewelry, it usually consists of a three digit number, most commonly 750 or 585. If you want to find out what that number means, and if you are curious about gold and golden jewelry in general, you came to the right place.
The basics.
Gold is a chemical element with the symbol Au. Au comes from the latin word for gold, aurum. In nature, gold may be found in the form of nuggets or grains inside rocks and aluvial deposits. In it's natural form, gold is a bright, shiny element, yellow in colour, with a slightly reddish tone. It is soft, and, out of all metals, most easily moldable. It is a relatively rare precious metal, commonly used as a currency, coinage and in art. It is the earliest recorded metal ever used, it's usage dating as far back as the Paleolithic era, which occured about 40.000 years ago. For the past six thousand years, it's use is common, and spread throughout the world. Today, the largest producers of gold in the world are China, Australia and Russia, while the largest consumer of gold is India, followed by China, the United States and Turkey. Gold has a vast range of use, from tools and weapons throughout history, to common use in technology in the modern age.
Due to it's durability, high melting point and beautiful shine, it is one of the most common precious metals used to make jewelry. But because pure gold is soft and easily breakable it is mixed in with other metals, into what is called an alloy. This alters the hardness, ductility and colour of the gold, making it easier to work with, in order to make jewelry. The metals used to mix gold into alloys are known as base metals, of which most commonly used is copper. Other metals commonly used in alloys are silver and palladium. The latter two make white gold alloys, while alloys containing copper are yellow or slightly reddish.
Gold purity, karats, hallmarks
If gold is not mixed in with other metals, we call it pure gold – it contains 100 % of gold. The higher the percentage of other metals in the alloy, the less pure is the gold product. This is called gold purity or finesse – the amount of pure metal in an alloy, in comparison to the full weight of the alloy. The most common way to measure gold purity is in karats. The word karat is derived from the latin word carratus, the word for the fruit of the carob tree. These fruits were used as a currency in medevial arabic world.
Karatage tells you what fraction of the alloy is pure gold. It works on a 24 fracture system. What this means is that 24 karat gold consists of twenty four parts gold out of 24 parts that make up the whole alloy. Therefore, 24 karat gold is 100 percent pure gold. The larger the amount of other metals in an alloy, the lesser the karatage. For example: 18 karat gold, means that the alloy is 18 parts gold, and the rest, in this case six, are other metals. This equals 75 % pure gold. 14 karat gold means 14 parts of the alloy are gold, and 14 are other metals, making the gold's purity 50%. Other common gold alloys are made from 12, 10 and 8 karat gold.
In order to certify the content of gold, or other noble metals in an alloy, items are stamped with an official mark, or hallmark. Traditionally they are punched into the metal, but more modern techniques use 2D and 3D printers. Hallmarks vary from country to country. In the United States, golden jewelry is marked with karatage and you will find stamps like 18K, 14K, ect. In the United Kingdom, they use the spelling carat, so jewelry will be stamped with marks like 18c, 14c, ect.
The rest of Europe follows the millesimal system of finess. What that means, is that instead of using a 24 karat fraction system, like the United States or the United kingdom, we use a 1000 fraction, or a millesimal system. This tells you how much grams of pure metal is there in 1000 grams of alloy. For example: 24 K gold or 100 % gold on a millesimal system equals to 1000 permilles. Therefore the hallmark on 24 karat gold produced in the European union will be 1000. 22 karat gold, or 91,6 % gold, equals 916 on the millesimal finesse system. The EU hallmark for 18 karat, or 75 % gold, is 750. This is the most common hallmark found on jewelry, along with 585 or 14 karat gold. 417 is the millesimal marking for 10 karat gold, and 333 for 8 karats.
So how much is my piece of jewelry actually worth?
To find out how much you can get for your piece of gold jewelry, or, if the jewelry you have your eye on is worth the price, you can google »pawn shops near me« and have it evaluated. But, since your knowledge about gold is no longer on a beginner level, you have most of the information you need to calculate the price of gold in your favourite necklace by yourself. To determine the value of gold metal inside an item we use what is called the gold calculator. The information you need to have before you calculate the value are the weight of your golden piece of jewelry, it's purity, and the current price of gold per troy ounce. To calculate the price, you have to follow three steps: first, you convert the weight of the gold alloy into troy ounces – you multiply the weight of the item by the troy alloy conversion factor, which can be easily found online. Then you convert the weight of the gold alloy into the weight of gold metal, by multiplying the weight of the alloy in troy ounces by gold purity in percentage. So if your necklace or earrings is marked with 750, that’s 75% pure gold. You then devide the result by 100. In the third step, you calculate the value of gold metal inside the alloy, by multiplying the weight of gold metal by the current price of gold metal per gram. The price is easily found online, but be sure to keep up to date, because the price can vary drasticaly from day to day.
So there you go. The 750 mark on your jewelry gives you all the information you need, to know how pure your jewelry is and how much it's worth.
