‘KDM’ in gold refers to the metallic element Kadium, or more commonly referred to as Cadmium. When a gold item is sold with the KDM label, for example, it simply means that this particular piece of gold was soldered with the use of KDM or Cadmium. For jewelry experts, labeling gold jewelry with ‘KDM’ is necessary in order to ensure that people will know what type of gold they are buying. Cadmium, or KDM, is considered toxic by some experts, and this why some people do not buy gold jewelry with the KDM label.
KDM, or Cadmium, is a common soldering agent used by many jewelry makers around the world because of its properties. Cadmium is popular because of its very high liquidity and its ability to melt at very low temperatures. These properties make it very ideal for soldering gold jewelry. Although other elements and metals may be used for soldering gold, Cadmium continues to become a popular choice despite its reputation as being toxic to the skin.
Gold jewelry that is soldered with Cadmium can be identified by the KDM label. When a jewelry item, for example, is labeled as ‘916 KDM,’ it simply means that this particular item is soldered with the use of Cadmium and contains 91.6% of gold. For people who have sensitive skin, buying KDM labeled gold jewelry may not be the best option, but people should not equate the KDM label with gold purity and quality. Cadmium is only used for soldering, and it does not affect the carat reading or gold quality. If gold quality and purity are the only concerns, one must accept the KDM label and focus on the hallmark label of the jewelry piece. Gold items that are said to be “hallmarked” are those that are certified in terms of purity. In this sense, KDM gold may also be hallmarked for its purity.