Once you understand a few important basics, you'll be well on your way to determining not only if a piece of gold jewelry is real, but equally important tidbits like gold content (purity) and thus, value.
The first term we'll look at is "karat", which is a standard unit used to measure the purity of gold. It works on a sliding scale up to 24k (pure gold), although you typically won't see jewelry marked less than 10k (older pieces do go lower). A higher number of karats means the item contains more gold, and lower numbers means less gold. So if you have a 10k gold pendant that is the identical SIZE of another pendant made of 18k gold, the 10k pendant will not only contain LESS GOLD, it will WEIGH LESS.
In order to find the gold content in a piece of jewelry, you first must know the karat purity. You can check out the section on Identifying Real Gold Jewelry Markings if you'd like the become familiar with how to spot real gold and tell exactly how much gold is in an item.
Once you know the karat purity of a piece of gold, simply divide that number by 24 and the result equals the percentage of pure gold contained in the item... represented in decimal form.
Say you have a large men's wedding band, marked "14KT". 14 divided by 24 is 0.58333... Move the decimal two places to the right and the number is now a percentage. In this case, the 14 karat gold wedding band is 58.333% PURE GOLD.
The same can be done no matter the karat marking...
- 10k / 24k = 0.41667 = 41.667% PURE GOLD
- 12k / 24k = 0.500 = 50.00% PURE GOLD
- 14k / 24k = 0.58333 = 58.333% PURE GOLD
- 18k / 24k = 0.7500 = 75.00% PURE GOLD
- 22k / 24k = 0.91667 = 91.667% PURE GOLD
So, once you know for sure that the piece in question IS SOLID GOLD, and the PURITY IS KNOWN, the GOLD CONTENT is quickly found per the table above. Since gold is soft and very malleable, jewelry is rarely made with more than 75% pure gold (18 karat jewelry) but 22k pieces do exist and are out there. (Keep an eye out for those, they offer one heck of a concentration of wealth in a small package!)
The next step is to figure out the value of the gold in your piece of jewelry. This is covered in more depth in another section and is the next recommended step to becoming a Gold Jewelry Guru!