ترکیب کانی‌شناختی و شیمیایی تورمالین مناطق نجم‌آباد، قشلاق، هیرد، ماهرآباد- خوپیک و ارتباط آن با نوع کانی‌سازی، شرق ایران

Tourmaline is present as alteration and mineralization at Maherabad and Khopik Cu-Au prospecting areas, Najmabad Sn-W-Au prospecting areas, Hired Au-Sn prospecting area, and within Gheshlagh pegmatite dikes. Based on X-ray diffraction graphs, Maherabad, Gheshlagh and Hired tourmaline are schorl, but Najmabad and Khopik are dravite type. Based on chemical composition, all of tourmalines belong to alkali group. The Mg/(Mg+Fe) ratio in Gheshlagh tourmaline is 0.21-0.29, in Hired is 0.32-0.47 and  in Maherabad is  0.44-0.5 and in  Najmabad and Khopik are Mg/(Mg+Fe)= 0.55-0.82. Khopik tourmaline contains considerably higher Mg (1.9-2.3) compared with the Maherabad (Mg = 1.4-1.9). The average TiO2 content of Maherabad tourmaline is 0.35 and Khopik is 0.19. At Khopik, deeper portion of the porphyry Cu-Au is exposed. Najmabad tourmaline contains the highest Mg (Mg= 2.2) and Gheshlagh the lowest Mg (Mg=0.5-0.7) and highest Fe (Fe= 1.9-2.3). Najmabad tourmaline contains the highest TiO2 (0.48%) and other tourmaline contains less than 0.3 % TiO2. In general, there is a reverse correlation between CaO and Na2O. Gheshlagh has the lowest CaO and highest Na2O. The CaO and Na2O content of tourmaline from Hired are very variable.