Diascope is a compact jeweler's microscope for the examination of loose and set diamonds in dark field and in incident light (Fig 154).
|In the development of this type of
microscope special importance was attached to intense halogen
illumination In the dark field device. This also permits longer
working time without fatigue. The powerful indirect illumination
of the stone also makes the smallest inclusions clear. A large
diaphragm is available for reducing brilliance, and it can be
adjusted down to illumination of dot-shaped size.
Fig 154 DIASCOPE Diamond Stereo Microscope (Elckhorst system)
The most remarkable feature about its equipment is the co-axial
annular incident light lamp with a color temperature of 5500°K.
Adjustability for height with a rack and pinion permits variable
adjustment of reflection
image of the diamond and hence an optimum perusal independent of the reflecting or dark facets. The entire annular lamp with rack and pinion can be swiveled away fully from the work area, thus ensuring maximum working comfort. A built-in dimmer permits stepless variation of the luminous intensity.
The body of the microscope can be tilted for stepless individual settings of eyepiece height to suit the viewer and thus permit long and relaxed work with the microscope.
The Diascope is delivered by the manufacturer with a Nikon stereo zoom optical system with 5 to 45 x magnification. Other proven instruments are also optionally available. With the wide-field eyepieces the field of view extends to 23 mm at 10 x magnification, has high contrast and is sharp as far as the edges. The large depth of field coupled with the three-dimensional image makes for a viewing comfort which has now become a general standard.
One small but rather important detail regarding the handling of diamonds is the stone holder. It is held magnetically by a steel ball which can be moved in any direction. A slightly stronger movement of the thumb suffices to remove it. The tips of the tweezers-shaped stone holder are provided with a rubber covering to prevent the diamond from "popping out".
The eyepiece for viewing cut stones is a useful accessory with which proportions can be determined in accordance with GIA standards.
|Gemolite||The DZ 9 M diamond microscope|