sapphire

We often recommend that novice gemologists send gems that are difficult to identify to a laboratory for testing. Gemological and mineralogical…

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…

Although gemstone magnetism isn’t a commonly tested gemstone property, it may be useful for making quick separations outside the lab. By Richard…

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,…

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…

The polariscope is one of gemology’s simplest and most useful tools. With a little practice and our three-part polariscope guide, you’ll…

Gemologists use liquids with high refractive indices (RI) to ascertain gemstone RIs and, thus, help identify and distinguish them. In addition,…

Step 3: Practical Gemology Lesson 4 Back to syllabus Gemstone identification is like detective work. You gather clues and eliminate suspects…

We tend to take light for granted. It’s such a common thing we experience every day. Rarely do we think of the scientific definition of light…