Karat: A variation of the word “carat”, (used to describe the weight of a gemstone), “karat”, with a “k” is used to describe the purity of gold. Gold is often alloyed with silver, copper, and/or other metals to improve its strength and durability. Products made from gold are marked to show how much actual gold is contained in the product. Items marked 24K are 100% pure gold. Items marked 18K or 750 have 750 parts gold out of 1000, or 75% pure gold. Items marked 14K are required by United States law to have 585 parts out of 1000, or 58.5% pure gold. 14K gold that meets this requirement is referred to as “Plum”, (meaning “best choice”), gold. Foreign industries which manufacture gold jewelry may produce items that are only 12K to 12 1/2K and sell them as 14K gold. When buying 14K gold jewelry, be sure to look for the 585 mark to assure the proper gold content. Items marked 417 are 10K gold. Much of the jewelry manufactured before the 20th century do not have these marks and must be tested to determine purity.

Karats are to do with the purity of gold other alloys are added to gold to give it strength the higher the karat the less alloys added to the gold

Wieght of 99.9% pure gold to alloy metal per gram.