What are Allochromatic and Idiochromatic Gems?
Learn the difference between allochromatic and idiochromatic gems and why some gem species can occur in many color varieties and others occur…
Mechanical Gemstone Cleaning
Mechanical gemstone cleaning has benefits and risks. Learn all about ultrasonic, steam, and boiling systems and how gems might react to them.…
A Gem Identification Quiz for Novice Gemologists
Learning how to identify gems involves more than just data. This gem identification quiz can help novice gemologists learn how to choose tests…
Destructive Acid Testing
In some cases, a hot point test won’t distinguish plastic simulants from natural gems. Some plastics release a protein smell when hot point…
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,…
Gemstone Physical Properties
The optical properties of gems attract our eyes and can give a cut stone a unique character. However, gemstone physical properties are also important.…
Turquoise Symbolism
Many people consider beautiful sky blue turquoise stones to be lucky. Learn about the turquoise symbolism and lore of Native American and other…
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