to make a solution of, as by mixing with a liquid; pass into solution: to dissolve salt in water. to melt; liquefy: to dissolve sugar into syrup. to undo (a tie or bond); break up (a connection, union, etc.). to break up (an assembly or organization); dismiss; disperse.
The Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly. The samples of matter used by Mohs are all different minerals. Minerals are pure substances found in nature. Rocks are made up of one or more minerals.
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.