Abstract: A method of producing alkoxysilanes and precipitated silicas from biogenic silicas is provided. In a first step, biogenically concentrated silica is mixed with a liquid polyol to obtain a mixture, and then the mixture is heated. In a second step, a base is added to obtain a reaction mixture. In a third step, the reaction mixture is filtered to remove the carbon enriched RHA or other undissolved biogenic silica and recover the solution of alkoxysilane and alcoholate. In a fourth step, alkoxysilane is purified by filtering, distilling, precipitating or extracting from the original reaction solution to precipitate various forms of silica. In a final step, residual base present in alkoxysilane is neutralized to eliminate the residual alkali metal base.