Gold is a precious metal that does not change in color, rust, corrode or fade and it can be molded to any shape.
Weight Precious metals are measured in ounces by an ancient troy standard. This standard is also used by pharmacists and medical professionals:
1 troy ounce= 480 grains= 20 pennyweights= 1.097 avoirdupois ounces= 31.103 grams Purity Gold is a very soft metal. To strengthen it, gold is often mixed with one or more additional metals called alloy. Alloys are usually copper, silver, or nickel. These alloys not only strengthen the gold but they also determine the color of the gold. For example, yellow gold will contain copper, and white gold will have nickel, zinc and copper mixed in. With these concepts, gold can come in many colors such as pink gold or also know as rose gold, or purple gold etc.The purity of gold is measured from 1-to-24 karats. 24 karat (24K) is the purest form of the metal, meaning it is 100% gold with no alloy. 18k gold means 18/24 karat, which is 75% gold and 25% alloy. Therefore, the lower the karat in gold means there is a greater amount of alloy. In the United States, an item must be at least 10K to be called gold. Jewelry or items less than solid 14k are considered costume jewelry and would not be eligible for trade.