In situ analysis of garnet inclusion in diamond using single-crystal X-ray diffraction and X-ray micro-tomography
Nestola, Fabrizio; Merli, Marcello; Nimis, Paolo; Parisatto, Matteo; Kopylova, Maya; Stefano, Andrea De; Longo, Micaela; Ziberna, Luca; Manghnani, Murli
European Journal of Mineralogy Volume 24 Number 4 (2012), p. 599 - 606
published: Aug 1, 2012
ArtNo. ESP147052404005, Price: 29.00 €
A single crystal of garnet enclosed in a diamond from the Jericho kimberlite (Slave Craton, Canada) has been investigated using X-ray diffraction and X-ray micro-tomography. The novel experimental approach allowed us to determine the crystal structure of the garnet. The unit-cell edge a and fractional atomic coordinates of oxygen were used to determine the composition via an updated Margules model for garnets. The composition is Pyr0.41(5)Alm0.36(7)Gro0.22(1)Uva0.01(1), which is indistinguishable from the eclogitic garnets found in other Jericho diamonds. We also demonstrated that residual pressures on the inclusion of up to 1 GPa do not affect significantly the determination of the garnet composition by structure refinement.