Imagine a silver that is brighter than platinum, white gold and traditional sterling; a metal that rarely needs polished because it doesn't tarnish or become dull. This is what Middlesex's Peter Johns did, but he did more than imagine it – he invented it. For the master silversmith and metallurgist took an alloy called germanium, added it to silver and produced Argentium.
It's a story that begins with a telephone call that dates back to 1989. Metaleurop – looking to find new uses for special metals they mined and refined – contacted Johns. "They offered two metals for research in the jewellery industry: indium and germanium. It turned out I chose the right one – germanium. One of the main uses for germanium is night vision systems – a market that dramatically diminished after the Cold War finished," explains Johns. "A lot of people think pure silver is sterling silver. But it's not. Pure silver alone is too soft to use. Humans first started adding copper into silver to make it harder about 5,000 years ago. The Romans also used copper to harden silver in very similar silver alloy compositions to ones we use now. The English established the sterling standard of 925 parts silver in the 1300s."
But sterling silver had a big problem: firestain and tarnish. "Most sterling silver is silver-plated to hide firestain. But when I began to work with germanium, I discovered that it eliminated firestain. It did this by forming a transparent self-regenerating germanium oxide on the surface that also resisted tarnishing," Johns says. "Everybody wants to stop silver tarnishing because people don't like cleaning it. For the last 100 years people have tried basically everything in the periodic table to stop it."
Johns embarked on more than ten years of research which resulted in Argentium, a patented formula using a higher combination of silver than traditional sterling, along with germanium and a unique combination of other elements. "Argentium has unique low temperature hardening properties and is also easily fused and welded, affording techniques that are normally difficult with silver because of its high conductivity and reflectivity. It also brings a safer working environment to the industry as it eliminates the need for the hazardous chemicals used in plating."
In 2004, the university launched a spin-off company that began to market Argentium Silver. That same year it won the AJM award for innovation at the New York Expo. In 2008, the university sold the project to private investors, though it retains a share. The new company is called Argentium International Ltd.
Johns is rightly proud of his invention. "Argentium is used across the world, not just to make jewellery, but silverware, sculptures and now even flutes. Argentium has its own sound, which works beautifully for musical instruments," says Johns. "It has been quite a remarkable journey. One that we couldn't have gone on without the University. There would be no Argentium without Middlesex."