Levasil CB25 A is a neutral, aqueous dispersion of colloidal silica that is approximately 30% solids by weight. The silica dispersion is sodium stabilized and the amorphous silica particles carry a negative surface charge. The silica particles are discrete, have a slightly rough, spherical shape, and are present in a narrow particle size distribution. The particles have also been surface modified with aluminum. The physical appearance of the dispersion is a translucent liquid, slightly more viscous than water. Levasil CB25 A is produced for world-wide distribution.