Mica Production: While India is a significant producer of mica globally, it is not the largest producer. China and Brazil are major competitors in mica production. India holds a substantial share in the production of high-quality mica sheets.
Limestone and Cement: Limestone is indeed the primary raw material for the cement industry. It constitutes about 80% of the raw material mix, along with clay and other additives. The quality and composition of limestone directly impact the properties of the cement produced. Major limestone-producing states in India include Rajasthan, Madhya Pradesh, Andhra Pradesh, Gujarat, and Chhattisgarh.
Classification of Limestone: The statement 'If limestone contains more than 10% magnesium, it is called gypsum' is incorrect. Limestone containing a high percentage of magnesium is termed dolomitic limestone or dolomite. Gypsum is a completely different mineral, a hydrated sulfate of calcium (CaSO₄·2H₂O), and is used in cement production as a retarder, and also in plaster of Paris and fertilizers.
Geographical Significance: Understanding the distribution and properties of minerals like limestone and mica is crucial for Indian geography. These minerals are vital resources for various industries, contributing significantly to the Indian economy.
