Microscopic Examination
Overview
Microscopy is the most important tool for identifying gemstones, detecting treatments, and determining natural vs. synthetic origin. Internal features (inclusions) tell the gem's story.
How It Works
A gemological microscope uses darkfield illumination to reveal internal features. Fiber optic lighting and immersion can enhance visibility of inclusions and growth patterns.
Equipment Needed
- Gemological microscope (10x-70x)
- Darkfield illumination base
- Fiber optic light source
- Immersion cell and liquid
- Stone holder/tweezers
Procedure
- Clean the gem thoroughly
- Start at low magnification (10x) for overview
- Use darkfield illumination to see inclusions clearly
- Increase magnification to examine specific features
- Rotate the gem to observe from multiple angles
- Document findings with photographs
Typical Values / Results
| Gemstone | Value / Observation |
|---|---|
| Natural Ruby | Silk (rutile needles), fingerprints, crystals |
| Synthetic Ruby | Curved striae, gas bubbles |
| Natural Emerald | Three-phase inclusions, jardín |
| Treated Emerald | Filler in fractures, flash effect |
| Diamond | Crystals, feathers, clouds, naturals |
Limitations
Clean, high-quality gems may lack diagnostic inclusions. Some treatments are designed to be undetectable. Experience is essential.