Silicate minerals
Topic: Minerals, Rocks and the Rock Cycle · NCERT: Beyond NCERT
Meaning
Silicate minerals are minerals built from units of silicon and oxygen, the two most common elements in the Earth's crust. Other elements such as aluminium, iron, calcium, sodium, potassium and magnesium join these units. Silicates make up over 90% of the crust, so they are the main building blocks of most rocks. The major groups are feldspar (the most abundant), quartz, mica, pyroxene, amphibole and olivine.
Example
The Peninsular Gneiss at Lalbagh, Bengaluru (a GSI National Geological Monument) is made almost entirely of silicates: feldspar, quartz and mica. Mica, another silicate, is mined in the Koderma–Gaya–Hazaribagh belt of Jharkhand and Bihar for electrical goods.
Don't confuse with
- Non-silicate minerals: calcite (calcium carbonate, found in limestone) and hematite (iron oxide) contain no silicon–oxygen units, so they are not silicates.