Cast basalt reaches a value of hardness of 8( min ) on the Moh's hardness scale. for comparision : the highest value10is only attained by dimonds. by virtue of these properties,the silicate cast basalt provides outstanding protection against abrasion and scrubbing.however, it is marked by asertain sensitivity ti impacts.Under Normal services conditions, cast basalt withstands tempratures up to approx.+ 350C