silicon dioxide (SiO2); silica
diatomaceous earth; diatomite; siliceous marl; kieselguhr
sodium silicate (Na2SiO3)
red and white-speckled silica
silicon tetrachloride (SiCl4)
pneumonoultramicroscopicsilicovolcanoconiosis; pneumonoultramicroscopicsilicovolcanokoniosis
siliceous sponge (any sponge other than those of class Calcarea)