What kind of Silicate gives the reaction between waterglass solution and RE-Chloride?

I made an experiment with diluted waterglass and diluted Ce(III)Chloride solution.

Transparent grains formed immediately which showed the typical blue luminescence of a Ce+3 presence of a Cerium(III)Silicate. Dried in air these grains rapidly lost this property and turned yellowish brown. This is obviosly an oxidation reaction to a Ce4(IV)Silicate.

It would be interesting to know its chemical formula. Any ideas?

Thanks in advance.