Silicate

noun
1.
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.
2.
Chemistry. any salt derived from the silicic acids or from silica.
noun
1.
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

silicate sil·i·cate (sĭl’ĭ-kāt’, -kĭt)
n.
Any of numerous compounds containing silicon, oxygen, and one or more metals; a salt of silicic acid.
silicate
(sĭl’ĭ-kāt’)

Any of a large class of chemical compounds composed of silicon, oxygen, and at least one metal. Most rocks and minerals are silicates.

Any mineral containing the group SiO4, either isolated, or joined to other groups in chains, sheets, or three-dimensional groups with metal elements. Micas and feldspars are silicate minerals.