Gem elbaite as a recorder of pegmatite evolution: In situ major, trace elements and boron isotope analysis of a colour-zoning tourmaline crystal

Zheng，Beiqi1,2; Chen，Meihua3

2021-11-01

10.3390/cryst11111363

Crystals   影响因子和分区

2073-4352

Few studies have focused on gem-quality tourmaline acting as a petrogenetic recorder, and the colour genesis of pink elbaite is still controversial. We carry out in situ major, trace element and boron isotope composition analyses on a single tourmaline crystal. This crystal is characterized by sudden transformation from colourless to pink, which can represent full pegmatite magma evolution. According to the analysis results, all spots are divided into alkali groups according to X-site occupancy and subdivided into elbaite series. The pink part accommodates higher concentrations of volatile and incompatible elements. The result is most consistent with successive pegmatite evolution in which the colourless part crystallized from the early stage, while the pink part crystallized from the late stage. The relatively consistent δ B value between the colourless and the pink part suggests no fluid exsolution occurred during pegmatite evolution. The slight increase of δ B values within the pink part and the colourless part may be due to mica crystallization. The combination of (Li +Mn) (Al +X)- and the exclusive positive linear relationship of Mn vs. Ti indicate that Mn is the main cause of pink, while Mn-Ti intervalence charge transfer also plays an important role.

Boron isotope Colourization mechanism Evolution Substitution

英语

通讯

2-s2.0-85119006439

Scopus

1.School of Environment,Harbin Institute of Technology,Harbin,150090,China
2.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,518055,China
3.Gemmological Institute,China University of Geosciences,Wuhan,430074,China

Zheng，Beiqi,Chen，Meihua. Gem elbaite as a recorder of pegmatite evolution: In situ major, trace elements and boron isotope analysis of a colour-zoning tourmaline crystal[J]. Crystals,2021,11(11).

Zheng，Beiqi,&Chen，Meihua.(2021).Gem elbaite as a recorder of pegmatite evolution: In situ major, trace elements and boron isotope analysis of a colour-zoning tourmaline crystal.Crystals,11(11).

Zheng，Beiqi,et al."Gem elbaite as a recorder of pegmatite evolution: In situ major, trace elements and boron isotope analysis of a colour-zoning tourmaline crystal".Crystals 11.11(2021).