Question

Use of diamond as a gem depends upon its
(a) High cost
(b) Refractive index
(c) Extreme hardness
(d)Bad conductance​

Answer 1

Extreme hardness is the answer

Answer 2

Use of diamond as a gem depends upon its

(c) Extreme hardness

•Diamond has a high scratch hardness because diamonds are made of carbons,so they form as carbon atoms under high pressure and high Temperature ,they bond together to start growing. They are so close and can't move due to their strong rigid covalent bond which make the diamond extreme hard.