Mineralogy. any of the largest group of mineral compounds, as quartz, beryl, garnet, feldspar, mica, and various kinds of clay, consisting of SiO 2 or SiO 4 groupings and one or more metallic ions, with some forms containing hydrogen. Silicates constitute well over 90 percent of the rock-forming minerals of the earth's crust.
Chemistry. any salt derived from the silicic acids or from silica.
a salt or ester of silicic acid, esp one of a large number of usually insoluble salts with polymeric negative ions having a structure formed of tetrahedrons of SiO4 groups linked in rings, chains, sheets, or three dimensional frameworks. Silicates constitute a large proportion of the earth's minerals and are present in cement and glass