Consider the following minerals:1. Bentonite2. Chromite3. Kyanite4. SillimaniteIn India, which of the above is/are officially designated as major minerals?

The correct answer is 2, 3, and 4 only. As per Govt. of India Notification S.O. 423(E) dated 10th February 2015 Bentonite has been declared as 'Minor Mineral'. Hence statement 1 is not correct. 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 earthUsed 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 andalusite are anhydrous aluminosilicate minerals that have the same chemical formula Al2O3 but DIFFER in the crystal STRUCTURE and physical properties.