It is pretty hard but crushes in your hands if you push hard enough !!!!! :D :) :P
Unprocessed or unrefined salt present in natural or raw state.
Salt is extracted from salt mines (the mineral is called halite) or from sea waters.
The unrefined sea salt has a very small amount of iodine.
where is rock salt on the moths hardness scale
Salt for human consumption is produced in three different forms: unrefined salt (such as sea salt), refined salt (table salt), and iodized salt.
There are more classifications possible to be made:solubillityacidicitycolor, hardness,mono, di, tri .... ionic Saltsdouble salts (with two or more metal ions)complex Saltsetc. (maybe more)
1.Refined salt, 2.Unrefined salt 3. Table salt 4.salty condiments 5 salt additives.
Two methods:- comparison with other materials with known hardness- using a special instrument to measure hardness
The Mohs hardness of of NaCl is 2,5.
Salt is sometimes used to remove water hardness. Borax and soda are generally used as well to remove water hardness.
Temporary hardness of water: CaHCO3, MgHCO3 Permanent hardness of water: CaSO4, MgSO4
It exchanges 2 ions of salt for every ion of hardness (calcium and magnesium). When the salt is exhausted, a backwash occurs that flushes the hardness ions to waste, replenishes the bed with fresh salt ions and starts all over again.