The hardest substance in a rock would be the hardest mineral of which the rock is composed.
10 is the hardest mineral on the scale. Since Mohs understood this to be the diamond (based on tests scratching different minerals) the diamond was designated a 10.
Diamond is the hardest mineral anywhere!
Diamond is the hardest known mineral, which is a physical property of the mineral.
The answer is a dimond
The hardest mineral is diamond, and the softest mineral is talc.
The hardest mineral is diamond, and the softest mineral is talc.
Diamond is the hardest mineral known.
Silicon Dioxide (known as Quartz) is not the hardest mineral, the hardest mineral is an allotrope of carbon called diamond. Quartz is only the 7th hardest mineral.
Diamonds are the hardest mineral and the agate is the secod hardest mineral.
Diamond is the hardest mineral on earth.
Diamonds are the hardest mineral, but not the 'strongest'.
Canada, which is north of Washington, is the home to a number of diamond mining operations. The mineral diamond is as hard as a mineral gets.
The hardest substance in a rock would be the hardest mineral of which the rock is composed.
The softest known mineral is 'TALC'. The hardest known mineral is 'DIAMOND' (according to Friedrich Mohs scale)
A diamond and talc
The diamond is the hardest rock (or mineral).