Secrets of Olympic Medal Minting
All the 6000 medals for the 2008 Olympics Games have arrived in the capital from the Shanghai Mint, ready for their debut on August 8. For the first time in Olympic history, the medals for the Beijing Games blend metal and jade.
Inlaying jade
The Shanghai Mint, under the China Banknote Printing and Minting Corp, works mainly in casting metal coins for circulation, and precious metal badges. It is the provider not only of the medals for the Olympic Games and Paralympics, but also of the medals for demonstration events, and commemoration badges.
For the first time in Olympic history, the medals for the Beijing Games blend metal and jade. The technology of inlaying jade into metal can be dated back to the Han Dynasty almost 2000 years ago.
Blending metal and jade is a new technique in minting coins. It is not easy to bond jade perfectly with metal. The key to the process lies in the inner layer of the medal metal and the groove of the jade ring. A seal ring is put between the inner layer and the groove to join the metal and jade together. The seal can also buffer the effect of vibration to protect the jade against impact.
Working with jade
The Jade ring must be matched with the medal metal, so it must comply with the necessary outer and inner diameters. Jade rings used for casting Olympic medals have been subject to rigorous quality controls, and those not up to the standard have been discarded.
To make use of those jade rings that do meet the quality criteria, metal medals were produced to fit the jade rings, and more than ten different sizes of seal ring were designed. (more…)

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