R7: Petrology, Mineralogy and Economic geology (Joint Session with Society of Resource Geology)

[R7P-05] Chemical composition of tourmaline from Li-pegmatite of Myokenzan, Ibaraki prefecture, Japan.

*Hotaka Ishizawa¹, Takuya Echigo¹, Yasushi Watanabe¹ (1. Akita Univ. )

Keywords:Tourmaline, Myokenzan Li-pegmatite, Elbaite, Schorl, EPMA-WDS

The chemical compositions of tourmaline from lithium pegmatites at Myoukenzan, were analyzed using EPMA. The tourmaline samples from this deposit can be classified into five types: black, indigo, dark green, watermelon, and pink. For each type of tourmaline samples, chemical composition was measured and the apfu was calculated. Our resutls identified those tourmaline as schorl-elbaite series. In addition, as the differenciation evolved, Fe tends to decrease and Li and Al tends to increase. This difference in chemical composition can be reflected as the difference in color.