What exactly is a karat?

Karats/carats are the most commonly used type of gold grade classification. Ultimately, the higher the karat the better the gold, and the better the gold, the more value it has. A karat is measured as 24 times the purity by mass. A karat is a measurement of the fineness of gold, and one of the core evaluation factors when it comes to deciding how much your gold jewelry or coins are worth on the market.

To evaluate the karat of your gold, divide the mass of pure gold or platinum in the material by the total mass of the material and multiply this number by 24. 24 karat gold is extremely fine (99.9% pure gold) and is worth more than any other type of gold. Most Continental European jewelry ranks somewhere around 18 karats, and the lowest acceptable number for gold jewelry is 8 karats. If you are unsure of the weight and mass of your gold items, your local jewelry store owner or jewelry appraiser can easily help you find these numbers out.

All gold jewelry in the United States and the United Kingdom are required by law to be stamped with the karat amount so consumers know exactly the grade of jewelry they are purchasing. This has not always been mandatory, so thousands take their family heirlooms or antique-shop bought gold jewelry to jewelry appraisers each year for karat evaluation. While America always uses the “karat” classification for jewelry, other countries use a fineness stamp and make note of the fineness in the gold instead. Fineness can easily be converted into a percentage, which can then be classified into its own karat category.

An example of this would be: Imagine you purchased a gold locket with a Fineness number of 917 stamped on the back. Simply place an imaginary decimal point after the last number, move this decimal point over one space, and what you’re left with is an estimated percentage of gold in your jewelry. In this case, 91.7% is the percentage of gold in the locket. Although this is an estimate, it is a great launching point for you to begin your karat investigation. Tables can be found all over the internet with estimates on what percentages equate to which karats. For example, one table shows that jewelry containing 91.66% of gold is equivalent to being 22 karats.

So gather up that gold jewelry and use the above steps to find out exactly how many karats your new piece of jewelry is!