Explanation:

• Top 5 States in terms of total coal reserves in India are: Jharkhand > Odisha > Chhattisgarh > West Bengal > Madhya Pradesh. On the basis of carbon content it can be classified into following three types:
• Anthracite: It is the best quality of coal with highest calorific value and carries 80 to 95% carbon content. It ignites slowly with a blue flame and found in small quantities in Jammu and Kashmir.
• Bituminous: It has a low level of moisture content with 60 to 80% of carbon content and has a high calorific value. Jharkhand, West Bengal, Odisha, Chhattisgarh and Madhya Pradesh have deposits of Bituminous.
• Lignite carries 40 to 55% carbon content and is often brown in colour with high moisture content thus, gives smoke when burnt. Rajasthan, Lakhimpur (Assam) and Tamil Nadu has deposits of Lignite.
• Peat is the first stage of transformation from wood to coal with low calorific value and less than 40% carbon content.

Coal reserves are widely distributed across India

• The Damodar Valley Coalfield- It is the largest coal reserve in India. The coalfield area includes the states of Jharkhand and West Bengal. Jharia of Jharkhand is the largest coalfield of India. Most of the coking coal in India is obtained from here. Other coalfields in Jharkhand are Jayanti, Bokaro, Karanpura, Ramgarh, Giridh, Auranga, Hutar, Deltenganj and Deogarh. Major coalfields in West Bengal are Raniganj (oldest coalfield of India) and Dalingkot in Darjeeling district.
• The Son Valley Coalfield- The region of Madhya Pradesh and some areas of Uttar Pradesh are included in it. Prominent coalfields in the Son Valley are Singrauli, Sohagpur, Umaria, Pench, Ramkola and Tatapani.
• The Mahanadi Valley Coalfield- The areas of Chhattisgarh and Odisha are included in it. Major coal mining areas in Chhattisgarh are Korba, Jhilmil, Chirmiri, Vishrampur, Lakhanpur, Sonhat, Birampur and Sonhat. Talcher, Rampur-Himgir and Ib river coalfield is the prominent coalfields in Odisha.
• The Godavari Valley Coalfield- The region is in the states of Andhra Pradesh and Telangana. Major coalfields in the region are Singreni, Tandoor and Sasti.
• The Wardha Valley Coalfield- Kampti, Wunfield, Chandrapur, Yavatmal, Nagpur are major coal mining areas located in Maharashtra.
• The Satpura Coalfield- The region is in the Satpura range, south of the Narmada river. Major coal mining centres are Ghorbari, Mahapani and Patharkheda.
• The Rajmahal Coalfield- Major coal-mining centre in the Rajmahal range is Lalmatia where open-cast mining is practised.

Source: NCERT