Which mineral substance placed at number 10 in Mohs scale

Answer: Option D

Diamond is the mineral substance placed at number 10 on Mohs scale.
The Mohs hardness scale was developed in 1822 by Frederich Mohs. This scale is a chart of the relative hardness of the various mineral (1-softest to 10-hardest).
Diamonds also show a variation in hardness (the octahedral faces are harder than the cube faces). Mohs hardness is a measure of the relative hardness and resistance to scratching between minerals.