Gold pricing is based on a number of factors, including karat amount (called karatage), gram weight, design and craftsmanship. The karatage and gram weight designate how much gold is in a piece, but are not the sole determining price factors. The craftsmanship and level of detail in a piece are also taken into account. Remember, a price based solely on gram weight does not reflect the work that has gone into the piece.
The most critical thing to look for in buying gold jewellery (aside from the style you like!) is the purity of the gold. The higher the gold content, the more valuable it is. The amount of gold in a piece is represented in the karat mark, usually inscribed on the back of the piece (e.g. 24K, 22K, 18K, 14K, etc.). The European system uses numbers representing a fraction of 1000, so “750” would be 75% gold, or the equivalent of 18 Karat. In addition to the karat mark, every piece of gold jewellery should be stamped with a hallmark or trademark of its manufacturer and sometimes its country of origin. In the United States, 14 karat gold, or 583 parts pure gold, is the most common degree of fineness and pieces are marked 14K. Nothing less than 10K can legally be marked or sold as gold jewellery in the U.S. However, lower karat, such as 9 karat gold and 8 karat gold, are popular in other countries.