Chapter 29, Problem 55A

To determine

To Explain: The causes of brilliant sparkle of a diamond.

Answer to Problem 55A

The brilliance sparkle of diamonds is anoutcome of total internal reflection.

Explanation of Solution

Introduction: Change in the direction of light or bending of light when it (light) travels from one medium to different medium, known as Refraction. Angle of incident in any optically denser medium for which angle of the refraction is right angle, called critical angle.

When light passes (or go through) from one medium of larger refractive index into one of the smaller refractive indexes, refracted ray always bends away from normal.

When a diamond is shaped as a gemstone, light that enters at one facet is usually totally internally reflected numerous times, without any loss in intensity, before exiting from another facet in another direction.

Because of unusually low speed of the light in a diamond, small critical angle and pronounced refraction produces a wide dispersion as well as wide array of clear colors. So, causes of brilliant sparkle of a diamond are mentioned below:

• Its high index of refraction
• Small critical angle.

Conclusion: Light travels very slowly in a diamond.