A biogenic silica from a plant material such as rice hulls, rice straw and so forth containing a significant amount of silica for use as an anti-caking agent, excipient or flavor carrier. When the plant material is certified as organic, the silica may also be certified as organic. The plant material is ground and the silica may be concentrated by carbon reduction through enzymatic treatment or burning. In some instances an antimicrobial treatment of the silica may be beneficial.