Journal ArticleDOI
Conversion of Quartz to Tridymite
TLDR
The conditions under which tridymite becomes a stable phase have been investigated in this paper, and the results showed that the formation of trithymite can be strictly a solid state process.Abstract:
The conditions under which tridymite becomes a stable phase have been reinvestigated. When quartz was heated with 2% alkali oxide, tridymite formed directly at 872° to 898°C. with Na2O, at 883° to 902°C. with K2O, and above 1005°C. with Li2O. Cristobalite occurred as an intermediate phase above 893°C. with Li2O, above 898°C. with Na2O, and above 902°C. with K2O. When quartz plus sodium chloride was heated in vacuum, tridymite did not form but cristobalite started to appear at 1050°C. The results showed that the formation of tridymite can be strictly a solid-state process. New schematic tentative diagrams for the high-silica region of binary systems are suggested. Quartz and cristobalite are regarded as the only stable crystalline phases of pure silica. Tridymite is pictured as a binary incongruently melting phase.read more
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Journal ArticleDOI
Thermodynamic properties of quartz, cristobalite and amorphous SiO2: drop calorimetry measurements between 1000 and 1800 K and a review from 0 to 2000 K
TL;DR: In this paper, relative enthalpy measurements on quartz, cristobalite and amorphous SiO2 between 1000 and 1800 K were reported, and the authors derived a consistent set of thermodynamic data for these phases.
Journal ArticleDOI
Structure of mineral glasses—I. The feldspar glasses NaAlSi3O8, KAlSi3O8, CaAl2Si2O8
Mark Taylor,Gordon E. Brown +1 more
TL;DR: In this paper, the short range distribution of interatomic distances in three feldspar glasses has been determined by X-ray radial distribution analysis and the resulting radial distribution functions (RDF's) are interpreted by comparison with RDF's calculated for various quasi-crystalline models of the glass structure.
Journal ArticleDOI
Oxygen mobility in silicon dioxide and silicate glasses: a review
TL;DR: In this article, the authors reviewed the literature concerning oxygen permeation and diffusion through amorphous and crystalline silicon dioxide, and silicate glasses, and collected data for diffusion coefficients to facilitate the assessment of probable dominant oxygen transport mechanisms, and associated rates.
Journal ArticleDOI
Silicic volcanism on Mars evidenced by tridymite in high-SiO2 sedimentary rock at Gale crater
Richard V. Morris,David T. Vaniman,David F. Blake,Ralf Gellert,Steve J. Chipera,Elizabeth B. Rampe,Douglas W. Ming,Shaunna M. Morrison,Robert T. Downs,Allan H. Treiman,Albert S. Yen,John P. Grotzinger,Cherie N. Achilles,Thomas F. Bristow,Joy A. Crisp,David J. Des Marais,Jack D. Farmer,Kim V. Fendrich,Jens Frydenvang,Trevor G. Graff,J. M. Morookian,Edward M. Stolper,Susanne P. Schwenzer +22 more
TL;DR: Tidymite, a low-pressure, high-temperature SiO2 polymorph, was detected in a drill sample of laminated mudstone (Buckskin) at Marias Pass in Gale crater, Mars, by the Chemistry and Mineralogy X-ray diffraction instrument onboard the Mars Science Laboratory rover Curiosity.
Journal ArticleDOI
Alignment Controlled Growth of Single-Walled Carbon Nanotubes on Quartz Substrates
Jianliang Xiao,Simon Dunham,Ping Liu,Yong-Wei Zhang,Yong-Wei Zhang,Coskun Kocabas,Lionel C. H. Moh,Yonggang Huang,Keh Chih Hwang,Chun Lu,Wei Huang,John A. Rogers +11 more
TL;DR: Advanced implementations of single-walled carbon nanotubes growth on crystalline quartz substrates with different orientations are examined, to yield strategies for forming diverse, but well-defined horizontal configurations of SWNTs.
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