This dark field device is suitable for microscopes of the A.KRÜSS MSL series and MSZ series.
Dark field microscopy is used to make the outlines of transparent or low-contrast inclusions visible. Here the direct transmitted light is blocked and the stone is only illuminated from the side. This lateral light is reflected and scattered at the inclusions and makes them particularly clearly visible. The result is a light image against a dark background. By observing inclusions, sites can be determined, stone qualities determined and forgeries or manipulated stones can be identified.
Practical examples of how sapphires are analyzed with dark-field microscopy or how crystallized rutile needles are observed can be found in the application article: Determining localities with stereomicroscopes .
There is also a practical tip for viewing inclusions with a stereo microscope (bright field microscopy). In the Methods article Microscopy you will find background information on examinations with stereomicroscopes and microscopy with immersion liquid.