Question

Explain the following :
Diamonds sparkle for some time in the dark.

Answer 1

• Total internal reflection: The phenomenon due to which a ray of light, while traveling from an optically denser medium to an optically rarer medium, gets reflected into the optically denser medium, at the surface of separation is called total internal reflection.
• Diamond is cut in such a way that a number of refracting surfaces are present and total internal reflection takes place at a number of places and as the critical angle of the diamond is $24°$, cuts at very sharp angles are made.
• As a result the ray gets trapped within the diamond for some time and thus making it shine.