Explanation:

Giridih is known to be rich in coal, and has many small and big coal mines in and around the town. After 1972 when the town was separated from the Hazaribagh district, Giridih became its own headquarters.

Jayankondam is a Second Grade Municipality in Ariyalur district of Tamil Nadu in India. It is also called Gangaikonda Cholapuram. As of 2011, the town had a population of 33,945. Huge amounts of lignite deposits have been found here and power projects have been initiated by the Neyveli Lignite Corporation.

Alwar is fairly rich in mineral wealth; it produces marble, granite, feldspar, dolomite, quartz, limestone, soap stone, barites, copper clay, copper ore and pyrophylite.

Dharwar System [4 – 1 Billion Years].They are the oldest metamorphosed rocks. Found in abundance in the Dharwar district of Karnataka. Economically the most important rocks because they possess valuable minerals like high grade iron-ore, manganese, copper, lead, gold, etc.