From circa 1965 Dutch jewellery designers experimented with new forms and (non-precious) materials. The appropriation of unremarkable objects for making a jewel also became an innovative point of departure. A famous example of this approach is this necklace by Gijs Bakker made of corner pieces of an aluminium stovepipe. While the anodization (a chemical process) of the aluminium changed its colour, it also provides a protective coating.