Reprinted with permission from the Goldmiths' Company Technical

Bulletin Issue 2 2005

Germanium silver is a sterling silver alloy invented by Peter Johns ¹ at Middlesex University, containing 1.2% germanium in place of some of the copper. This alloy gives excellent protection against fire stain by the formation of a germanium oxide layer on heating which is transparent. In addition, it is tarnish-resistant even under very arduous conditions.

This is because a passive layer is formed by the germanium on the alloy which significantly slows the formation of silver sulphide. Germanium silver is also found to have the following advantages over sterling silver:

• Easier to solder due to the suppression of copper oxide

• Cost savings on finishing as there is no requirement to strip or plate over fire stain

• Superior ductility as demonstrated by the Erichsen cupping tests

• High tensile strength

• Ease of welding owing to the decreased heat conductivity and the lower oxidation potential reduces the need for inert cover gas when welding²

• Heat-hardenability

However, there are differences between germanium and sterling silver. These include: