Koktokay No. 3 (Altay No. 3) pegmatite, Altay Mine, Koktokay (Keketuohai) Pegmatite field, Fuyun Co., Aletai (Altay) Prefecture, Yili Hasake (Ili Kazakh) Autonomous Prefecture, Xinjiang (Xinjiang-Uygur) Autonomous Region, China

A highly evolved, rare-element class, LCT-type granitic pegmatite of the spodumene-subtype category. Exploited for pollucite, spodumene, lepidolite, beryl and columbite-tantalite.

The Koktokay No. 3 pegmatite intruded metagabbro. It shows a well-developed internal textural zonation, both in the thin but extensive subhorizontal bottom section, and in the cupola. From the outermost textural zone inward, nine mineralogical-textural zones can be distinguished: (1) graphic pegmatite zone; (2) sugary albite zone; (3) blocky microcline zone; (4) muscovite-quartz zone; (5) cleavelandite-spodumene zone; (6) quartz-spodumene zone; (7) platy albite-muscovite zone; (8) lepidolite-platy albite zone; (9) blocky quartz and microcline core (Wang et al. 1981; Zhu et al. 2000; Wang et al. 2006).

Ref.:
- Huanzhang Lu, Zhonggang Wang, and Yuansheng Li (1997): Magma-Fluid Transition and the Genesis of Pegmatite Dike No.3, Altay, Xinjiang, Northwest China. Chinese Journal of Geochemistry 16(1), 43-52.
- Zhu, J.C., Wu, C.N., Liu, C.S., Li, F.C., Huang, X.L., and Zhou, D.S. (2000): Magmatic-hydrothermal evolution and genesis of Koktokay no. 3 rare metal pegmatite dyke, Altai, China. Geological Journal of China Universities 6(1), 40-52 (in Chinese with English abstract).
- Zhang, A.C., Wang, R.C., Hu, H., Zhang, H., Zhu, J.C., and Chen, X.M. (2004): Chemical evolution of Nb-Ta oxides and zircon from the Koktokay no. 3 granitic pegmatite, Altai, northwestern China. Mineralogical Magazine 68(5), 739-756.
- Liu Cong-Qiang, and Hui Zhang (2005): The lanthanide tetrad effect in apatite from the Altay No. 3 pegmatite, Xingjiang, China: an intrinsic feature of the pegmatite magma. Chemical Geology 214(1/2), 61-77.
- Wang, R.C., Hu, H., Zhang, A.C., Fontan, F., Zhang, H., and de Parseval, P. (2006): Occurrence and late re-equilibration of pollucite from the Koktokay no. 3 pegmatite, Altai, northwestern China. American Mineralogist 91, 729-739.
- Wang, R.C., Hu, H., Zhang, A.C., Fontan, F., de Parseval, P., and Jiang, S.Y. (2007): Cs-dominant polylithionite in the Koktokay #3 pegmatite, Altai, NW China: in situ micro-characterization and implication for the storage of radioactive cesium. Contributions to Mineralogy and Petrology 153, 355-367.
- Tao Wang, Ying Tong, Borming Jahn, Tianren Zou, Yanbin Wang, Dawei Hong, and Baofu Han (2007): SHRIMP U–Pb Zircon geochronology of the Altai No. 3 Pegmatite, NW China, and its implications for the origin and tectonic setting of the pegmatite. Ore Geology Reviews 32, 325-336.