Gemstone Examination Lesson
Learning how to conduct a gemstone examination takes practice. Follow an expert gemologist step-by-step through tests of five unknown samples.…
The Dichroscope: A Faceter’s Guide
A dichroscope can distinguish the colors of pleochroic gems. Learn how gem cutters can use this tool to choose the best faceting designs for these…
Advanced Gemology Equipment
We often recommend that novice gemologists send gems that are difficult to identify to a laboratory for testing. Gemological and mineralogical…
Destructive Testing with a Streak Plate
Gemstone streak testing is fun if you have rough material to spare. It’s not recommended for finished gems, as there’s a good chance…
Gemstone Magnetism
Although gemstone magnetism isn’t a commonly tested gemstone property, it may be useful for making quick separations outside the lab. By Richard…
Physical Properties of Gemstones
Step 2: Advanced Gemology Lesson 2 Back to syllabus The optical properties of gems attract our eyes and can give a cut stone a unique character. However,…
Color Filters for Gem Testing
A set of color filters is easy to pack for any gem buying trip, but did you know they can be useful in the lab, too? In this article, you’ll learn…
What is a Polariscope?
The polariscope is one of gemology’s simplest and most useful tools. With a little practice and our three-part polariscope guide, you’ll…
Gemstone Refraction Liquids
Gemologists use liquids with high refractive indices (RI) to ascertain gemstone RIs and, thus, help identify and distinguish them. In addition,…
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