'Salt ranks at 2 1/2 --midway between gypsum & calcite-- on this scale that measures hardness'
the Mohs scale
SALT: Salt ranks at 2 1/2 --midway between gypsum & calcite-- on this scale that measures hardness
Salt ranks at 2 1/2 --midway between gypsum & calcite-- on this scale that measures hardness
Salt ranks at 2 1/2 --midway between gypsum & calcite-- on this scale that measures hardness
SALT
the Mohs scale
SALT