KDM: Gold Jewelry from some places is / was marked with a KDM stamp which means that the Jewelry was soldered with Cadmium. Cadmium called 'Kadium' in some places and marked KDM was traditionally used in soldering of gold jewelry for its good properties of liquidity and melting at lower temperatures, which is not the case any more as Cadmium is known to create toxic fumes when melted, which are very dangerous to health, over a period of time and may be harmful to humans, making the gold jewelry, some countries have banned the use of Cadmium from use, from workshops. Jewelers in many parts of the world now use gold solders, which are free from Cadmium. Please note that the wearer of the gold jewelry is not harmed, this issue only concerns the manufacturing process. Also note that using any type of gold solder either KDM (Cadmium) or other gold solder, to make the jewelry does not guarantee the purity of gold, as the purity is a representation of the percentage of gold in any metal.
In the traditional method, silver and copper were used to solder gold. But many jewellers have switched over to cadmium since it gives good melting fluidity during the soldering process.
Even customers prefer KDM gold, as loss or wastage of gold during the soldering process is minimum because cadmium gets readily dissolved
Jewellery workers using cadmium have experienced problems like cough, irritation in throat, gastroenteritis, vomiting, wheezing and anorexia.
Toxic fumes released when gold is soldered with cadmium can damage the health of the workers