It's almost pure carbon, it does in fact absorb some waterborne impurities. (not that I would trust it over modern filtration/sterilizatiom).
Shungite has been used as a folk medical treatment since the early 18th century. Peter the Great set up Russia's first spa in Karelia to make use of the water purifying properties of shungite, which he had himself experienced. He also instigated its use in providing purified water for the Russian army. The anti-bacterial properties of shungite have been confirmed by modern testing.
"EMF protection"...not so much. These nutters need to all be put in a giant farady cage and wonder why "my phone don't work".