Talk iz serpentinita Studenice i Rajca (Srbija)

The Talc from the serpentinite of Studenica and Rajac (Serbia)

Abstract

The paper piesents the results of a research on talc from the serpentinite in the valley of the Studenica River and froin the serpentinite of Rajac Mt. The studied and described occurrences of talc represent pure steatites and contribute to the knovvledge of this mineral species. Unit-cell parameters (Å) for talc are: from the Studenica a_o=5,310 (5), b_o=9,10 (2), c_o=18,95 (8), ß=99,2 (2)°, V_o=905,35 (2) ų; from Rajac a_o=5,310 (5), b_o=9,12 (2), c_o=18,94, ß=99,2 (2)°, V_o =908,01 (2) ų. Cristallo-chemical formula calculated on the basis of 24 (O, OH) is: (Mg_5,77, Fe²⁺_0,13, Fe³⁺_0,10, Ca_0,10, Na_0,02)^VI_6,12 (Si_7,73, Al_0,24)^IV_7,97 O _19,95 (OH)_4,05 for the Studenica talc, and (Mg_5,81, Fe²⁺_0,23, Fe³⁺_0,09, Ca_0,04)^VI_6,17 (Si_7,69, Al_0,24 )^IV_7,93O_19,94 (OH)4,06 for the Rajac talc.