While indirectly related to Himalayan salt caves due to their sourcing, Himalayan Salt Lamps are not quite the same. These lamps are sold for the dual purposes of mood lighting and supposed health benefits due to the generation of negative ions that "...help remove airborne contaminates." and "help mitigate EMF fields". Sometimes salt lamps are also alleged to work in the same way as an air ioniser.
Obviously, the aesthetics of salt lamps are subjective and can't be tested; however, is there any evidence the support the claim that the lamps remove airborne contaminates?