Q. Consider the following minerals:

  1. Bentonite
  2. Chromite
  3. Kyanite
  4. Sillimanite

In India, which of the above is/are officially designated as major minerals?

  • 1 and 2 only
  • 4 only
  • 1 and 3 only
  • 2, 3 and 4 only

Answer: d) 2, 3 and 4 only

Notes:

  • As per Govt. of India Notification S.O. 423(E) dated 10th February 2015 Bentonite has been declared as ‘Minor Mineral’.
  • The Central Government has declared the following minerals as minor minerals:
    • Boulder, shingle, chalcedony pebbles used for ball mill purposes only, lime shell, kankar.
    • And limestone used in kilns for the manufacture of lime used as a building material.
    • Murrum, brick-earth, fuller’s earth, bentonite, road metal, reh-matti.
    • Slate and shale when used for building material, marble, stone used for making household utensils.
    • Quartzite and sandstone when used for purposes of building or for making road metal and household utensils, saltpeter, and ordinary earth
    • Used or filling or leveling purposes in construction or embankments, roads, railways, building.
  • Bentonite is essentially a highly plastic clay containing not less than 85% clay mineral, montmorillonite.
  • Chromite (Cr) is the single commercially viable ore of chromium which is chemically known as iron chromium oxide (Fe.Cr2O4).
  • Kyanite, Sillimanite, and alusite are anhydrous aluminosilicate minerals that have the same chemical formula Al2O3 but differ in the crystal structure and physical properties.