Question

The basic reason for the extraordinary sparkle of a suitably cut diamond is that

Answer 1

the reason for the extraordinary sparkle in diamond is due to the cuts made in diamond is of suitable angle which leads to total internal reflection(TIR).Hence,due to such multiple reflections it shines!

Answer 2

in a diamond when a light ray is passed through it it experiences a total internal reflection where the all sides of diamond acts as reflecting side hence it is the basic reason for the extraordinary sparkle of a suitably cut diamond.