Lesson 3: Gemstone Color Change Phenomena


Step 2: Advanced Gemology

Lesson 3

Frequently, people ask me to explain how gemstone color change works. Some stones can change color under different light sources. Although the answer is pretty complex, a few diagrams can really help.

To understand how this phenomenon works, you need to learn about light and how gems get their coloration.

White Light and Colors

We know that sunlight or white light contains all colors. Pass a sunbeam through a prism and you’ll see a rainbow on a nearby wall. You can also consider light as energy. Visible light is closely associated with infrared, which heats us, and ultraviolet, which tans our skin.

Gemologists, as well as other scientists, use a spectroscope to separate light into it’s different components. If you were to look at the sun through a spectroscope, you’d see something like the image below. Each color is a slightly …

Unearth The Secrets Behind The Beauty

Introducing "Discover Gemology" by IGS, the premiere introductory training for those fascinated by the magnificent world of gemology.

  • How to spot the most unique & valuable characteristics of different gemstones
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Course: Discover Gemology: Fundamentals, Tools & Meanings
Purchase Course: $49
Skill Level: beginnner
Lessons: 48
Time: 480 min