The prototype of the iconic Tetrahedron lamp, designed by Frans van Nieuwenborg and Martijn Wegman in 1979. This is the model the designers built themselves. It was shown in 1979 in the Stedelijk Museum Amsterdam. After the exposition lighting company Indoor took it into production. What makes the prototype unique is the mirror on the bottom. It repeats the whole structure with a kaleidoscopic effect. And ofcourse the light is reflected upward.
As the name "Tetrahedron" implies it has the shape of a triangular pyramid. The light bulb is held by a smaller tetrahedron shape, suspended in the middle. Three glass sides of the pyramid are yet again held together by small, black tetrahedrons on the corners. (These are metal on this prototype. The ones Indoor produced are plastic ). On the corners the designers labelled it with black ink; not sandblasted into the glass like the ones Indoor produced.
It is in a very good condition. The mirroring foil underneath the mirror has some scratches, as the mirror is placed directly on the floor.