Garnet group minerals from the amphibolite facies metamorphic rocks of Krivaja-Konjuh ultramafic massif in Bosnia and Herzegovina

In amphibolite rocks, in the southern edge of Krivaja-Konjuh ultramafic massif, six samples are separated (from localities Stupcic I, Stupcic II, Pobilje, Donja Vijaka and Seliste) in which occurrences of minerals of chlorite group are confirmed using optical tests. Mineral composition of samples of rocks is checked using x-ray analysis on the instrument of brand Philips with CuKα radiation with graphite monochromator. Chemical composition of mineral-chlorite in rocks was determined using electronic microsonde (ARL-SEMQ). Analyses of chlorite were calculated in accordance with recommendations of HYPER-FORM (S. Borg, A. Moggesie and E-Bjerg, 1991). Calculation of formulas of chlorite was done on the basis of 28 O and 36 (O, OH). In Bosnia and Herzegovina, minerals of chlorite group are very frequent and developed compounds in igneous, sedimentary and metamorphic rocks. Even though they are mentioned in numerous petrography and mineralogy papers, most of the authors of petrography papers describe chlorites as members of the mineral groups, and articles where more detailed selection or description of certain types of chlorite are given are more rare. Quantity of chlorite in amphibolite rocks in the area of Vijaka is variable. Chlorite in amphibolite rocks in the area of Vijaka occurs in the shape of bands at contacts of amphibolite rocks with ultramafic rocks. In the crust of decaying of amphibolite rocks. As inclusions in corundum, garnets, amphiboles, pyroxene, plagioclase, and in celyphitic rim of garnets as a product of retrograde metamorphism in the hydrothermal conditions of metamorphism.