The X-ray powder diffractions, magnetic susceptibility chi and magnetization M were measured for the precipitate from the aqueous solutions of NiCl2.6H2O and Na2SiO3.nH2O. From the X-ray and magnetic analysis, the precipitate has the component of monolayer Ni(OH)2 with the diameter of 20-30 angstrom. The temperature dependence of chi and M showed a magnetic transition just above 10 K and field cooling effect.