On the basis of source of raw materials used, industries are classified into: 1.Agro-based industries: These industries are based on agricultural raw material, e.g., cotton, jute, silk, rubber, sugar, tea, coffee and edible oils. 2.Mineral-based industries: Industries that use minerals and metals as raw materials are called mineral-based industries, e.g., iron and steel, cement, aluminium, machine tools, petrochemicals, etc.