Question

The basic reason for the extra ordinary sparkle of a suitably out diamond is that.

• A. It is very hard
• B. It has a very high refractive index
• C. It has a very high transparency
• D. It has well-defined cleavage planes

Answer 1

The correct option is B It has a very high refractive index

Diamonds sparkle due to total internal reflection occuring when light travels from diamond to air. For, total internal reflection to occur, the transmitting material, in this case diamond must have a much greater refractive index than the medium it is placed in. Diamonds have a refractive index of $2.4$.