Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Mayank vedwal Vedwal
calcite has three set of cleavage which intersect at an angle of 105° in one plane and 75° in another plane. It is not not necessary to remeber the angle of intersection because it rarely asked in any competative exam. But if u can remember it then u should because everything has its specific use in geology.