What Is KDM Gold? The History and Shift in Purity Standards
Explore the evolution of gold purity standards, from a key historical manufacturing method to the safer, regulated practices used in modern jewelry.
KDM gold refers to a specific gold alloy historically used in jewelry making, where “KDM” stands for Kadmium, or Cadmium. It served a particular function in crafting intricate designs, influencing gold jewelry purity standards.
Understanding KDM Gold
KDM gold denotes jewelry where cadmium was used as a soldering agent. This allowed for high purity gold items, typically 91.6% or 92% gold content, often marketed as “92% KDM gold” for 22-karat pieces.
The inclusion of cadmium in the solder meant that a 22-karat gold piece, for instance, could maintain its 91.6% gold purity, even in areas where parts were joined. Before KDM gold, traditional soldering methods often lowered the overall gold purity of the final product. KDM gold thus represented a significant advancement in maintaining the intended gold fineness in finished jewelry.
The Technical Role of Cadmium
Cadmium played a technical role in gold jewelry manufacturing due to its properties. It possesses a lower melting point, approximately 321.1°C, compared to pure gold, which melts at about 1064°C. This difference allowed jewelers to melt the cadmium-containing solder without affecting the gold components.
This technical advantage preserved the purity and integrity of the gold item. Cadmium facilitated strong, durable joints for intricate jewelry designs. Its ability to flow easily at lower temperatures made it ideal for complex soldering, ensuring the gold’s original composition remained intact.
The Shift Away from KDM Gold
The jewelry industry transitioned away from KDM gold due to health and environmental concerns. Cadmium is a toxic heavy metal, and its use in soldering posed health risks to jewelers exposed to its fumes. Prolonged exposure could lead to respiratory issues, kidney damage, and other serious health problems.
Concerns also extended to consumers, as cadmium can be absorbed through the skin, potentially leading to adverse health effects. Environmental regulations and industry standards began to ban its use in jewelry manufacturing. Regulatory bodies, such as the Bureau of Indian Standards (BIS), led the adoption of safer, alternative soldering materials.
Modern Gold Purity Standards
Modern gold purity standards prioritize the precious metal’s content and the safety of materials used in crafting. Gold purity is assured through various certification and hallmarking systems. These systems provide consumers with confidence regarding the gold content and the absence of harmful elements.
Hallmarking involves stamping jewelry with marks indicating its gold fineness, such as “916” for 22-karat gold (91.6% pure), “750” for 18-karat (75% pure), or “585” for 14-karat (58.5% pure). Consumers should look for these hallmark stamps, often with a certifying body’s mark, when purchasing gold jewelry. This ensures authenticity and adherence to purity guidelines, reflecting safety and transparency.