Natural layered aluminosilicate pyrophyllite Al-2[Si4O10](OH)(2) has been used as a starting material for preparing Nasicon-type fast ion conductors in the Na1+3xAlxHf2-xSi2xP3-2xO12 system. Most of the synthesis reactions were performed at 900-1150 degrees C and with increasing value of x, lower reaction temperatures were used. A single : NASICON phase with a C-2/c space group has been found in the composition range x less than or equal to 0.6. The volume of the-unit-cell in this composition range increased with increasing x. The initial composition with x = 0.6 possesses maximum ionic conductivity which reaches values up to 1.22 x 10(-2) S . cm(-1) at 350 degrees C, with an activation energy of 26.3 KJ/mole.