Minerals Review Ruby Deposits: a review and Geological Classification Gaston Giuliani
Figure 11. Variations of the ruby trapiche texture. (A
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- Figure 11. Variations of the ruby trapiche texture. (A
| Figure 11. Variations of the ruby trapiche texture. (A) Variation of the core, which corresponds to the
pinacoidal growth sectors (in grey). These sectors have a tapered shape and the core size varies as a function of the orientation of the cross-section; (B) aspect of the section near the vertex of the pyramid; and (C) aspect of the section if cut in the vertex plane. Photos by Isabella Pignatelli of two trapiche rubies from Mong Hsu, Myanmar. Figure 12. X-ray computed tomography image showing the high porosity (in black) of a trapiche ruby from Luc Yen, North Vietnam [57]. The porosity corresponds to 0.6% of the ruby volume and is developed in the sector boundaries. Photo: Christophe Morlot. Tube-like voids filled with carbonates, liquid, and/or gas may be observed in the growth sectors (Figure 13) [51,57,62]. These can develop from the core or sector boundaries and extend into the growth sectors, running perpendicular to the sectors with an inclination of 5° relative to the {0001} ruby faces. Sometimes the tube-like voids can be parallel to the c axis. Garnier et al. [58,59] found single-phase (liquid), two-phase (liquid + gas), and three-phase (liquid + gas + solid) inclusions between the tube-like voids and/or their extensions into the sector boundaries. Microthermometry and Raman spectrometry indicate that these inclusions correspond to the trapping of two immiscible fluids during the ruby formation: a carbonic fluid in the CO 2 -H 2 S-COS-S 8 -AlO(OH) system and molten salts [62–64]. These fluids are considered the product of metamorphism of evaporites during the devolatization of carbonates and thermochemical-sulfate reduction. Figure 11. Variations of the ruby trapiche texture. (A) Variation of the core, which corresponds to the pinacoidal growth sectors (in grey). These sectors have a tapered shape and the core size varies as a function of the orientation of the cross-section; (B) aspect of the section near the vertex of the pyramid; and (C) aspect of the section if cut in the vertex plane. Photos by Isabella Pignatelli of two trapiche rubies from Mong Hsu, Myanmar. Baixar 8.58 Mb. Compartilhe com seus amigos:
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