What mineral has the least hardness according to the scale?
The Mohs Scale of mineral hardness lists the mineral talc at #1, the mineral of least hardness on the scale.
Minerals have a fairly specific range of hardness, based on the Mohs hardness scale. The Mohs scale is based on the ability of a mineral to be scratched, or scratch, another mineral. Using the Mohs scale to determine mineral hardness is one test that can be used to help identify one mineral from others.