| Diamond | Graphite |
| Diamond is the hardest substance on earth. | Graphite is soft and slippery |
| In diamond carbon is sp3 hybridised | In graphite carbon is sp2 -hybridized |
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| Since all the electrons in diamond are firmly In c-c, 6 bonds there are no free electrons in diamond crystal. Therefore diamond is bad conductor of electricity. | Since only three electrons of each carbon are used in making hexagonal rings of graphite, fourth valence electron is free to move thus graphite is a good conductor of electricity |
| Because of high refractive index diamond can reflect and refract the light. | Graphite is a black substance and posses a metallic luster. |
