When manufacturers using steel went looking for a new material for bikes Pinarello found magnesium. It is light and strong but difficult to work with. They dabbled with it for a few years until carbon took over. The last metal bike to win the Tour de France was a Pinarello magnesium Ak61 Dogma in 2006, ridden by Oscar Pereiro.. Here is a rare version called the Ego. This frame is currently for sale on Ebay:
Pinarello Ego