Inspection of rough precious stones - in immersion liq. through hole in specified plastic foil

摘要

Rough precious stones are inspected in an immersion liq. by a microscope through the central hole in a plastic foil floating on the liq. Pref. the plastic foil (120) has a central hole (122) and has a lower density than the immersion liq. (82), e.g. benzyl benzoate. It comprises transparent PE, 200 microns thick with a hole of 15-20mm dia.. The stand (10) for the container (80) holding the immersion liq. (82) with the rough precious stone (70) is made of rubber. A polarisation filter (18) is screwed to the microscope (8). ADVANTAGE - Reduces the differential refractive and total reflection phenomena and permits the observation in a vertical path of waves by microscope without great expense.