Fineness is proportion, expressed in parts per thousand, of the purity of gold, silver, and platinum in jewelry. i.e. Sterling silver is .925 silver and .075 copper. Jewelry is usually stamped in such a way as to indicate the fineness. These marks vary from country to country and are usually controlled by local laws. Some examples below:
14K is the Fineness Marking for Gold Items that are .585/1000 Pure Gold.
French “Dog’s Head” Mark Indicating Platinum.
PLAT Mark Indicating the Metal is Platinum.