Question

what is internal reflection of brilliance of diamonds???

Answer 1

It is also known as internal reflection. This cannot occur if light Travells from less dense medium to the denser one. Diamonds achieve their brilliance from total internal reflection.

Answer 2

This effect is called total internal reflection. But note that total internal reflection cannot occur if light is traveling from a less dense medium to a denser one. Diamonds achieve their brilliance partially from total internal reflection.