The article presents the research results dealing with the influence of such natural minerals as flint and shungite in relation to the following water parameters pH, TDS, conductivity, cations (NH4+, K+, Na+, Mg2+, Sr2+, Ba2+, Ca2+) and anions (Cl−, SO42−, NO3−, F−, СО32−). It was found that crushed flint and shungite added to the water more significantly increases water hydrogen index if compared to sedimentation. Simultaneously total water mineralization decreases (causing electric 28,4 al conductivity decrease). Considerable decrease in calcium ions concentration (by 36.0 %) was detected in the water infused with shungite and by 20.5% in the water infused with flint. Considerable increase in K+ ions concentration in water infused with flint (46.3%) was revealed. As for the anions F− concentration decreased for both minerals - shungite and flint. These natural minerals are recommended for the treatment of tap water characterized with the increased hardness and excessive fluoride ions content.