Maundy bowl, 1996.
© Science Museum / Science & Society Picture Library
During the 1990s, Mokume Gane, an ancient Japanese metal working technique, was reinvented using diffusion bonding. The bowl contains 21 layers of 'Mokume Gane' metal, comprising layers of nickel silver (60 per cent copper, 18 per cent nickel and 22 per cent zinc) and copper. It was raised with the pattern on the inside and patinated with ammonia vapour. The green colour is the diffused interface between the two metals. Made by Ian Ferguson.