Look for Karat Marks on the Earrings
The first thing you need to do in order to find out the karat of gold earrings is to look closely and see if there are any karat marks stamped on them. For example, a hallmark that reads “14K” or “14 Kt” means that the earring is made out of 14-karat gold.
Gold purity marks are not always in the form of karat stamps, however. It is not uncommon to see numbers such as 583 or 750 stamped on gold jewelry.
If your earrings have similar marks, then perhaps their purity is represented with parts-per-thousand numbers.
To convert parts-per-thousand purity to gold karats, multiply the number by 0.024.
Thus, you will see that the stamps reading 583 and 750 convert to 14K and 18K respectively.
Other common parts-per-thousand marks are 417 for 10K, 833 for 20K, and 917 for 22K. 24 karats, which is the karat of pure gold, is denoted by the number 999.
What Does the Karat of Your Gold Earrings Mean?
The karat number of your gold earrings denotes their gold purity.
Jewelry is not usually made with pure gold, as this metal is too soft. This is why gold is mixed with other metals to make the resulting alloy harder.
Different gold alloys can have different proportions of gold and other metals, and karat numbers convey information about the level of gold content in such a mixture.
As already mentioned, 24 karats is the highest possible value for gold purity.
So, a karat number tells you how many parts pure gold there are in an alloy out of 24 parts in total. For example, the meaning of 10 karats is that the alloy with this purity contains 10 parts gold and 14 parts other metals.
What If There Are No Karat Marks on the Earrings?
If there are no karat marks on your earrings, you can have them tested for gold purity – jewelers usually provide such a service. The other option is to test the pieces yourself with a gold testing kit.
Testing Gold Earrings at the Jewelry Store
If you go to a jeweler to determine the karat of your earrings, it is very likely that they will be tested with nitric acid.
A very small sample of the gold of your earrings will be taken, and some acid will be applied to it to see how the color of the gold will change.
Depending on the reaction of the metal with the acid, the karat number of your earrings will be determined.
Testing Your Earrings for Karats at Home
You can also find out the karat of your earrings at home, and one of the best ways to test them is with a gold testing kit.
Gold testing kits contain several bottles of nitric acid in different concentration, and each bottle will have a karat label on it.
If you rub your earring on the testing stone provided with the kit, the gold will leave a visible mark.
If you now drop some acid on it from one of the bottles and the mark changes its color, this means that the karat of the gold is lower than the number on the bottle’s label.
If the gold mark doesn’t change its color after being treated with the acid, this means that the karat is higher than what is written on the label of the bottle.
You should continue testing with the other bottles until the change in color is only slight – this is a sign that the alloy’s karat matches that on the label of the bottle.