Karat (K or kt): Karat is a unit of measurement used to denote the purity of gold in jewelry. It indicates the proportion of gold in an alloy out of a total of 24 parts. For example, 24 karat gold is considered pure gold (99.9% gold), while 18 karat gold is 18 parts gold and 6 parts other metals.
Carat (ct): Carat is a unit of measurement used to measure the weight of gemstones, such as diamonds. One carat is equivalent to 200 milligrams. The carat weight of a gemstone can affect its value, with larger stones generally being more valuable, assuming other factors like cut, clarity, and color are equal.
In summary, "karat" relates to the purity of gold, while "carat" relates to the weight of gemstones.