Gemological Microscope

The field lab workhorse — inclusions, fractures, treatments, and surface features at 10–40x

Typical price$ 200 - 1500

PortabilityLow portability

Field noteBench instrument, buying counter or lab

How to use it

Place the stone in the stone holder or tweezers on the microscope stage
Start at 10x magnification with overhead ring light for an overall surface and clarity assessment
Switch to darkfield illumination to reveal inclusions, fractures, and filled features
Increase magnification to 20–40x for detailed inclusion examination
Use side fiber optic or transmitted light to examine internal features in different lighting modes
Systematically scan from table to pavilion, rotating the stone throughout

Reading tips

Darkfield illumination makes inclusions and fractures glow against a dark background — the most useful mode for treatment detection
Overhead reflected light is best for surface features, coatings, and polish quality
Transmitted light from below reveals color zoning, growth structures, and assembled stone layers
A gemological microscope differs from an immersion microscope in that the stone is examined dry; immersion gives cleaner views but requires setup
Most practical tool for detecting oil in emerald fractures, flux residue in corundum, and lead-glass fill in ruby under strong side lighting