Which is the softest rock

Each mineral in the scale scratches the one below it the lower number but not the one above it the higher number. This became known as Mohs' scale of hardness , and is still one of the best practical methods of estimating a mineral's hardness. Mohs designated ten minerals for his scale from hardest 10 to softest 1 listed with objects of equivalent hardness :. Using moderate pressure, drag a sharp edge over the smooth surface of a mineral.

If the surface of the mineral is scratched then it is softer than the material used to scratch it, if not then it is harder. Citations 1. View Metrics. Notable Notes. March Access through your institution.

Add or change institution. Save Preferences. Privacy Policy Terms of Use. Access your subscriptions. Orthoclase: easily scratches glass and is just scratched by a file 7. Quartz: not scratched by a file 8. Topaz 9. Corundum Softest mineral.

Who Talc. Where Not Applicable. The scale reads as given below: Hardness Material: 1.