The Petroscope gives an insight into petrology (from greek πέτρα, pétra, rock). It exhibits the different structures in a stone and the spectacular display of colors that this dense material has to offer. The Petroscope projects an enlarge image of an thin section on the wall. The thin section is a flat piece of stone, of thickness between 20 to 30µm. This results in transparency go the opaque stone. By sliding the magnetically connected optics and light source, different projections of the thin sections can be observed. The optional insertion of polarizing filters causes the light to refract against the different minerals.