Because it's the most accurate ...!
This scale is correctly called the Mohs scale. Scientists use this scale to measure a rock's hardness or softness. They can discover how hard a mineral or rocks is and drill in to it and find out more about it.
Diatomite has a hardness of around 5.5 on the Mohs scale of hardness.
It's called the Ore
The hardness of Limonite is 4 t0 5.5 on the mohs hardness scale.
Azurite has a hardness of 3.5 to 4 on the Mohs hardness scale.
flint is a type of quartz, so it has a hardness of about 7 on the mohs scale of hardness
Nickel has a hardness of 4 on the Mohs scale.
The hardness is 3-4 on Mohs scale.
Dolomite has a hardness of 3.5-4 on the Mohs scale of hardness.
The Mohs scale is used to determine the relative hardness of minerals.
This scale was proposed by the Austrian geologist Friderich Mohs.
Aluminum Oxide is roughly 8.5 - 9.0 on the hardness scale.