The term 24-karat gold is a measure of the purity of gold. It is the highest level of purity, with 24 parts out of 24 being pure gold. This is often referred to as 'fine gold' or 'pure gold'. Karat is a unit of measurement used to indicate the proportion of gold in an alloy. The higher the karat number, the more gold is present in the alloy. 24-karat gold is the most valuable and sought after form of gold, as it is the purest form available.