How to Choose the Best Gemology Microscope

The most important piece of equipment in any gemologist’s equipment is a good microscope. 

Precious stones are defined by their flaws, but if you want to have any hope of finding them you’ll need the right gear for the job.

A good quality Gemology Microscope with the right features will let you see the inclusions, fractures and striae that would otherwise go unseen. But before you buy any old microscope, you should know what features you’ll need to make the best use of your gemological talents. 

Here are some of the more important qualities you should look for in a good gemological microscope.

Optico NGI-6 Gemology Microscope

Magnification

Most gemologists use 30–45x magnification for everyday appraisals. That’s high enough to see most of the relevant internal structures in a gemstone. However, for newer and higher quality synthetics, 80–90x magnification is often recommended.

Illumination

Your microscope should come equipped for darkfield and bright field illumination.

Darkfield illumination showcases a gem against a dark background. This technique places a stopper in the path of direct light from the light source, letting only oblique reflected light enter the sides of the gemstone.

In a flawless stone, the light would pass straight through and you would only see the dark background of the stop, but any imperfections scatter and refract the light – you end up with the imperfections clearly illuminated and well contrasted against the dark background.

Ideally, your microscope will also be able to handle bright field illumination. This method simply involves shining light directly into the gemstone from below.

This approach is useful for inspecting curved striae, zones of different colours and low relief inclusions. It can also be used if scratches or fine dust particles are obscuring proper darkfield inspection.

If you photograph your gems, you’ll want both kinds of illumination so you can highlight the best qualities of a gem while selectively hiding its flaws.

Lighting

A decent gemological microscope will have a light source in the base to let you use the various illumination techniques, but it can also be worthwhile having lighting above the stage too.

This secondary lighting is used to inspect the external features of gemstones, such as polishing marks, pitting and other marks that are found on the surfaces of gemstones.

It increases coverage and surface visibility while you’re working, and also provides a reasonable approximation of how a gem or piece of jewellery will look under normal indoor lighting when it’s being worn.

Trinocular Head

A trinocular microscope head has a built-in eyepiece specifically for attaching a camera. This is your best option if you’re into serious photography.

USB3 Digital Camera

For the highest quality imaging, you can attach a dedicated USB Digital Microscope Camera our recommended camera for the Optico Gemological Microscope is the MIchrome 6 Pro.

MIchrome 6 Pro - 6 Megapixels Resolution Camera

Accessories

Appraising gemstones and jewellery requires special accessories so that they can be easily held and manipulated.

Gemological microscopes often come equipped with a delicate set of jewel clamps or a built-in stand, but depending on your needs it can be worthwhile to get a specialised gemological stand or holder.

A good stand will give you the option to tilt and rotate a gemstone so you can easily inspect it from any angle. If you’re working with gems of unusual size or jewellery such as rings, you can also find stands that are designed to handle awkward sizes or shapes.

If you spend any length of time appraising or photographing gemstones or jewellery, a stand or holder for comfortable, hands-free viewing is a must.

If you find a gemological microscope with most of these features, you’ll be prepared for any kind of appraisal. Our recommended Gem Microscope is the Optico NGI-6:

NGI-6 Gemological Microscope

Professional Grade Gemological Microscope offers crisp high-resolution imaging with a zooming magnification range of 0.8x – 50x, with both bright field and dark field illumination, two reflected light sources (fluorescence & LED) and a 30W dark field halogen light built in to the base and a 7W gooseneck rectangular fluorescent incident light box that shines light directly onto your specimen, used to observe the surface details and fine structures of jewels or gemstones. The transmitted light through the dark field condenser is designed for the examination of the inside quality and inclusions of diamonds and other gemstones.

Up to 100x magnification can be achieved when fitting a 2x Barlow Lens.

Features Include:

  • Advanced optics offer enlarged field of view, depth of field and flatness of specimen
  • Leading edge design includes fixed prisms and a single-spindle zoom mechanism
  • External nylon-on-nylon gearing provides the smoothest zoom possible
  • Proven ergonomics for comfort during use
  • 45-degree trinocular head
  • 10x Extra-wide FOV fully adjustable eyepieces
  • Continuous range magnification (from 8x to 50x)
  • Halogen bright field/dark field illuminator; 7 watt fluorescent light for reflected illumination that simulates North Facing daylight for accurate color grading and an optional pin point, variable LED light on a flexible gooseneck
  • Inclinable stand with gemology stage, base rotates 0° – 325° and tilts 0° – 38°
  • Built-in darkfield condenser with iris diaphragm
  • Coarse focus controls with 110mm focusing range
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