The picture shows one of three units, fitted into a wall display, which was commissioned by the Naturbornholm Museum in Denmark.
The brief was to look at rock sections in polarised light. The visitor can rotate the disc protruding from the front of the unit, this holds the rock specimen. Just below the large viewing lens there is a smaller viewing window which allows the visitor to see the actual rock slice without magnification.
Different fragments in the rock are highlighted in various colours by the polarised light and the 10x magnification microscope shows every detail in the slice of rock.
