It’s happened to someone tell you that is a jewel of 14 gold or 18 gold? Come to the translation of what that means. Pure gold is a very, very malleable material. If you have a 100% gold ring and greet someone, a handshake, the ring will bend, becoming oval.
Of course no one wants a gem as well, so delicate that it seems made of play dough. So gold is mixed with other elements, such as copper, zinc, silver or palladium, forming an alloy. These metals determine the hardness of the alloy, but also affect the color of gold.
To set the amount of gold in an alloy, arose the expression carat or karat (K), 24k equals 100% gold, pure gold. If you talk to is a 18K gold jewel, it means it has 18 parts gold and 6 parts other metals, i.e., has 75% gold. Hence, too, the term 750 gold used more in Europe. So, 18K or 750 gold are the same thing. If the jewelry is 14K, that means it contains 14 parts gold, 10 other metals and so on.
If you look through the magnifying glass inside of a jewel, you’ll see that many of them bring a printed number. Many countries have specific legislation on the subject. In the United States, for example, is considered the gold jewelry Alloys above 10K.
Now, this karat (K) has nothing to do with the carat (ct) used to measure the weight of a gemstone. And this creates a damned mess, because K is a measure of purity and ct is a measure of weight, two totally different things within the same word carat. A CT equals 1/5 of the gram or 200 mg.