Thermochemistry of guest-free melanophlogite

@article{Navrotsky2003ThermochemistryOG,
  title={Thermochemistry of guest-free melanophlogite},
  author={Alexandra Navrotsky and Hongwu Xu and Eric C. Moloy and Mark D. Welch},
  journal={American Mineralogist},
  year={2003},
  volume={88},
  pages={1612 - 1614}
}
Abstract Melanophlogite is a naturally occurring clathrasil possessing a framework of linked silicate tetrahedra surrounding small, isolated cages, which can host small molecules. The energetics of a guest-free natural sample was determined by oxide-melt solution calorimetry. Melanophlogite is energetically metastable with respect to α-quartz by 9.5 ± 0.5 kJ/mol, a value similar to that for amorphous silica and for synthetic small-pore zeolitic silicas (Petrovic et al. 1993, Piccione et al… 

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