Argentium sterling silver
Argentium silver (patented in 1998) is a brand of modern tarnish-resistant silver alloys, containing either 93.5%, 94% or 96% silver. Argentium alloys replace some of the copper in the traditional sterling silver (92.5% silver + 7.5% copper) with the metalloid germanium.
Source: Wikipedia — Argentium sterling silver (CC BY-SA 4.0)