Mssbauer spectroscopic study of Fe-Mg tourmalines with different Fe contents

We studied four tourmalines with different Fe contents from Xinjiang,Sichuan,and Yunnan provinces of China using Mossbauer spectroscopy and single crystal X-ray diffraction.The valence and location of Fe in the four tourmalines and two heat-treated tourmalines have been investigated.The experimental results showed that Fe in the four tourmalines at room temperature had two valence states and two locations,i.e.Fe2＋（Y）,Fe2＋（Z）,Fe3＋（Y）.After being heated at 850℃ for 48 and 72 h,Fe elements in tourmaline were nearly completely oxidized and mainly occupied Y sites,and a small amount of Fe3＋ shifted to Z sites.Simultaneously,the amount of mixed valence state Fe 2.5＋ progressively increased with heating time,and electron delocalization occurred between the adjacent sites [Fe2＋-Fe3＋].

We studied four tourmalines with different Fe contents from Xinjiang,Sichuan,and Yunnan provinces of China using M ssbauer spectroscopy and single crystal X-ray diffraction.The valence and location of Fe in the four tourmalines and two heat-treated tourmalines have been investigated.The experimental results showed that Fe in the four tourmalines at room temperature had two valence states and two locations,i.e.Fe2+(Y),Fe2+(Z),Fe3+(Y).After being heated at 850℃ for 48 and 72 h,Fe elements in tourmaline were nearly completely oxidized and mainly occupied Y sites,and a small amount of Fe3+ shifted to Z sites.Simultaneously,the amount of mixed valence state Fe 2.5+ progressively increased with heating time,and electron delocalization occurred between the adjacent sites [Fe2+-Fe3+].