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GM Series

GM Series

Special stereo microscope setups for the inspection of gems and minerals. All GM systems are based on the respective stereo microscope, implementing a transmitted/incident illumination dedicated to the specifics of translucent precious stones.

Featured products

  1. GM-161 Binocular
    GM Series
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  2. GM-161 Trinocular
    GM Series
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  3. GM-168 Binocular
    GM Series
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  4. GM-168 Trinocular
    GM Series
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GM optics


The Greenough zoom systems start with a 6:1 zoom (GM161) and 20mm FOV up to a 6.7:1 zoom with 23mm Field of View (GM171). The total magnification can be extended with alternative eyepieces and auxiliary objectives up to 320x (GM168).

GM illumination


From plain stands without illumination to integrated Halogen/LED equipment for incident and transmitted light: diverse compact solutions for observation and documentation are available.

GM mechanics


The standard packages come with a head holder and a pole stand with Ø 32mm mounting. Focusing is done through a coarse focus with tension adjustment. The transmitted light stand with fiber optical port and tiltable mirror gives maximum illumination freedom.

Learn here how to adjust the tension of the focusing system.

GM accessories


A 10X micrometer eyepiece with diamond proportion analyzer is available for each GM microscope. Diverse gem holders and gemological tools like inclusion pointer, diffusor plate and immersion cells as well as specific polarization sets for the different models complete the range of accessories.