Chemical Composition and Molecular Formula of Rajmahal Bentonite (Jharkhand)

Abstract

Twenty six samples of bentonite of Rajmahal hills (Jharkhand) were studied for their percentage composition of constituents such as SiO₂, Al₂O₃, Fe₂O₃, TiO₂, P₂O₅, Na₂O, MgO, CaO and K₂O. These samples were collected from different places and available in different colours from Rajmahal hills. These samples contain high percentage of silica with lower limit of 34.64 % and higher limit of 56.24 % was comparable well with the literature values. Theoretical molecular formula was calculated and presented as (Si_aAl_b)(Al_cFe_dMg_e)Ca_fNa_gK_hO₁₀(OH)₂ where a = 2.57- 3.57, b = 0.42-1.43, c = 1.14-1.67, d = 0.10-0.56, e = 0.01-0.53, f = 0.03-0.48, g = 0.12-1.23 and h = 0.03-0.53. The theoretical formula of bentonite minerals of Rajmahal hills are reported for first time in literature.