Gemstone Optical Properties


Step 2: Advanced Gemology

Lesson 1

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 or its properties. However, in the gemological world, light plays a critical role. You must first understand the principles of light before understanding gemstone optical properties. Gemologists can analyze these properties for gemstone identification. They can also apply them practically when cutting gems for optimum brilliance and character.

The Properties of Light

Electromagnetic Energy

Light is part of the electromagnetic spectrum, one of the fundamental energies of the universe. It’s present everywhere in substantial amounts.

Light energy travels in waves. The energies on the electromagnetic spectrum differ simply by their wavelengths. Some are shorter, some longer. Wavelength has nothing to do with the amount of energy carried. Wave amplitude determines that. All wavelengths can be high or low in energy.

gemstone optical properties - electromagnetic energy

Although, in nature, all electromagnetic energy is essentially the same, varying wavelengths have different characters. For example, we relate to some as radio waves, others as X-rays. We see a very tiny part of the electromagnetic spectrum as light. Within this section, we perceive …

Premium Article

This is a Premium Article. Please become a member to read this entire article and gain access to hundreds more like it.

Membership options

Full Article Details


Content Length 5295 words
Reading time 26 min 29 sec

Here's what you get if you unlock this article:

  • The Properties of Light
    • Electromagnetic Energy
    • Refraction
    • Polarization
  • Selective Absorption
    • How Does Color from Selective Absorption Differ From Pigment?
    • The Spectroscope
    • Color Change
  • Refractive Index
  • Gemstone Inclusions and Refraction
    • Fractures and Refraction
    • Oiling and Refraction
  • Immersion Tests and Refraction
    • Estimating Refractive Indices of Immersed Gems
    • Viewing Inclusions in Immersed Gems
  • Critical Angle
  • Brilliance
  • Scintillation
  • Windowing
  • Double Refraction and Birefringence
    • Doubling
  • Crystal Habits and Refraction
    • Amorphous
    • Isometric
    • Tetragonal
    • Hexagonal
    • Orthorhombic
    • Monoclinic
    • Triclinic
    • Summary
  • Pleochroism
  • Dispersion
  • Luster
  • Optic Character
  • Fluorescence
    • Fluorescence and Gem Identification
    • Fluorescence and Gem Grading
  • Phenomenal Effects
  • Gemstone Optical Properties Self Test

Plus, additional member-only benefits:

  • Exclusive access to other premium articles and courses
  • Unlimited access to our gem pricing guide
  • Participate in our member-only forums
Membership options