Open Access Senior Honors Thesis
Geography and Geology
Christine Clark, PhD
Rick Sambrook, PhD
The tourmaline mineral group has a highly complex chemical composition and provides a wealth of information on Earth's processes. Past research has revealed numerous mysteries regarding the structure of the boron triangle within tourmaline, especially as it bonds to the Z- and Z'- cation sites. Although the Z- and Z' - are nominally the same site, the Z'-site has a greater effect on the stereochemistry of the boron triangle. Further, the Z' -site has a shorter bond-length with the boron triangle than the Z-site. We hypothesize that this variation affects the stereochemistry of the boron triangle, and have analyzed a database of tourmaline crystal -structure data consisting of 99 tourmaline samples representing 13 tourmaline species to determine the validity of our hypothesis. Overall, the data supports this hypothesis. It was found that the Z' -site forms a more linear angle with the boron triangle than the Z-site, allowing 2'- to have a greater effect on the stereochemistry of the boron triangle.
Badgerow, Charles J., "The Tilt of the Boron Triangle in Tourmaline" (2013). Senior Honors Theses. 330.