含铁较高的是淡黄色。不溶于水和酸（除氢氟酸），溶于氢氟酸而成四氟化硅气体，能溶于碱。 Silica nanoparticles have been used : ? To study the nonlinear optical properties of SiO2 nanocomposites in weak optical fields. ? As a nanoadditive in nanocomposite calcium alginate fibers. ? As dispersant in liquid polymethylsiloxane to exihibit unique optical non linearity in low intensity visible radiation fields.