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Opal, cristobalite, and tridymite: Noncrystallinity versus crystallinity, nomenclature of the silica minerals and bibliography

  • Deane K. Smith (a1)

Cristobalite and tridymite are distinct forms of crystalline silica which, along with quartz, are encountered in industrial operations and industrial products. Because the International Agency for Research on Cancer has designated “crystalline silica” as an IARC Group 2A (probable carcinogen) and quartz and cristobalite as a Group 1 (carcinogen), it is important to properly identify and quantify the silica phase in all materials used in production and encountered in products. Opal is a form of hydrated silica which is also encountered in industry. Although some forms of opal mimic cristobalite and tridymite, they are not truly crystalline. The term “silica” in the industrial sense is used to mean any material whose composition is SiO2 whether it is crystalline or noncrystalline. Some people also consider silica to include hydrated SiO2. There are many forms of SiO2 which have both long-range and short-range order and are recognized as crystalline phases among which are quartz, cristobalite, and tridymite. The hydrated silicas, on the other hand, pose an enigma. Only a few forms show sufficient long-range and short-range order to be considered crystalline. The mineral silhydrite is an example. Opal in all its forms lacks sufficient order to be considered crystalline. Even opal-C, which produces a X-ray pattern similar to the diffraction pattern of cristobalite, lacks not only sufficient order to be considered crystalline but also contains water in the structural make-up. This paper discusses a classification and nomenclature for these forms which is critical to proper regulation. It also reviews the recent literature on tridymite, cristobalite, and opal, and provides an extensive bibliography. Modern studies have shown that opal-A is disordered, but opal-CT and opal-C contain ordered domains that mimic stacked sequences of cristobalite and tridymite sheets such that X-ray patterns show features similar to the crystalline cristobalite and tridymite. There is debate on whether the ordered regions have lost the water that characterizes the opals. In fact, heating studies have shown that all opals show changes on heating characteristic of materials that lose water in the process. The TEM evidence showing domains in the range 10–30 nm in a matrix of disordered opal suggest that the proper term for this system is paracrystalline analogous to inorganic and organic polymers.

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Barth, T. F. W. (1932). “The cristobalite structures: I High-cristobalite,” Am. J. Sci. 23,350356.
Brindley, G. W. (1980). “Quantitative X-ray analysis of Clays,” in Crystal Structures of Clay Minerals and Their X-ray Identification, edited by G. W. Brindley and G. Brown (London, Mineralogical Society).
Cady, S. L., Wenk, H.-R., and Downing, K. H. (1996). “HTREM of microcrystalline opal in chert and porcelanite from the Monterey Formation, California,” Am. Miner. 81,13801395.
Darraugh, P. J., Gaskin, A. J., Terrell, B. C., and Sanders, J. V. (1965). “Origin of precious opal,” Nature (London) 209,1316.
De Jong, B. H. W. S., van Hoek, J., Veeman, W. S., and Manson, D. V. (1987). “X-ray diffraction and 29Si magic-angle spinning NMR of opals: Incoherent long- and short-range order in opal-CT,” Am. Miner. 72,11951203.
Dollase, W. A. (1965). “Reinvestigation of the structure of low cristobalite,” Z. Kristallogr. 21,369377.
Dwyer, F. P., and Mellor, D. P. (1934). “An X-ray study of opals,” J. Proc. R. Soc. N. S. W. 68, 47–50.
Elton, N. J., Salt, P. D., and Adams, J. M. (1992). “The determination of low levels of quartz in commercial kaolins by X-ray diffraction,” Powder Diffr. 7,7176.
Elzea, J. M., and Rice, S. B. (1996). “TEM and X-ray diffraction evidence for cristobalite and tridymite stacking sequences in opal,” Clays Clay Miner. 44,492500.
Elzea, J. M., Odom, I. E., and Miles, W. J. (1994). “Distinguishing well ordered opal-CT and opal-C from high temperature cristobalite by X-ray diffraction,” Anal. Chim. Acta 286,107116.
Flörke, O. W. (1955). “Zur frage des “Hoch-Cristobalit” in Opalen, Bentoniten and Glasern,” Neues Jahrb. Min. Mh. 217–233.
Flörke, O. W. (1967). “Die Modificationen von SiO 2,” Fortschr. Min 44, 181–230.
Flörke, O. W., Flörke, U., and Giese, U. (1984). “Moganite, a new microcrystalline silica mineral,” N. Jahrb. Min. Abh. 149, 325–336.
Flörke, O. W., Graetsch, H., and Jones, J. B. (1990). “Hydrothermal deposition of cristobalite,” Neues Jahrb. Min. Mh. 81–95.
Flörke, O. W., Jones, J. B., and Schmincke, H-U (1976). “A new microcrystalline silica from Gran Canaria,” Z. Krist. 143, 156-165.
Flörke, O. W., Jones, J. B., and Segnit, E. R. (1973). “The genesis of hyaline,” Neues Jahrb. Min. Mh. 82–89.
Flörke, O. W., Jones, J. B., and Segnit, E. R. (1975). “Opal-CT crystals,” Neues Jahrb. Min. Mh. 369–377.
Flörke, O. W., Graetsch, H., Martin, B., Bochum, K., and Wirth, R. (1991). “Nomenclature of micro- and non-crystaline silica materials, based on structure and microstructure,” Neues Jahrb. Mineral. Monatasch. 163, 19–42.
Frondel, C. (1962). The System of Mineralogy, Vol. III The Silica Minerals, 7th ed. (Wiley, New York).
Garavelli, C. L. (1964). “Ordine e disordine negli opali,” Atti. Soc. Tosc. Sci. Nat. 71, 3–56.
Gibbs, R. E. (1926). “The polymorphism of silicon dioxide and the structure of tridymite,” Proc. R. Soc. London, Ser. A 113,351368.
Goswami, G. (1997). Personal Communication, Talmia Institute of Scientific and Induistrial Research, Orissa, India.
Graetsch, H. (1994). “Structural characteristics of opaline and microcrystalline silica minerals,” in Silica, physical behavior, geochemistry, and materials applications, edited by P. J. Heaney, C. T. Prewitt, and G. V. Gibbs, Reviews in Mineralogy. 29. Min Soc. Am. 209–232.
Graetsch, H., and Flörke, O. W. (1991). “X-ray powder diffraction patterns and phase relationships of tridymite modifications,” Z. Kristallogr. 195,3148.
Graetsch, H., Flörke, O. W., and Miehe, G. (1985). “Wachstum, Struktur ind Gefuege von Opal-C bis-CT,” Z. Kristallogr. 170,5658.
Graetsch, H., Flörke, O. W., and Miehe, G. (1987). “Structural defects in microcrystalline silica,” Phys. Chem. Miner. 14,249257.
Guthrie, G. D., Bish, D. L., and Reynolds, R. C. Jr.(1995). “Modeling the X-ray diffraction pattern of opal- CT,” Am. Miner. 80,869872.
Heaney, P. J. (1994). “Structure and chemistry of the low pressure silica polymorphs in silica, physical behavior, geochemistry, and materials applications,” Reviews in Mineralogy, Volume 29, Mineralogical Society of America, Washington, DC, pp. 1–40.
Heaney, P. J., and Post, J. E. (1992). “The widespread distribution of a novel silica polymorph in microcrystalline quartz varieties,” Nature (London) 255,441443.
Hill, V. G., and Roy, R. (1958). “Silica structure studies. VI, On tridymite,” Trans. Brit. Cer. Soc. 57, 496–510.
IARC. (1987a). “Silica and some silicates,” Monogr. 42, International Agency for Research on Cancer. Lyon, France. 39–143.
IARC. (1987b). “Evaluation of the carcinogenic risks to silica and some silicates,” Monogr. 43. International Agency for Research on Cancer. Lyon, France.
IARC. (1997). “Silica, some silicates, coal dust, and para-aramid fibrils,” IARC Monographs on the Evaluation of Carcinogenic Risk to Humans, 68.
Jones, J. B., and Segnit, E. R. (1969). “Water in sphere type opal,” Miner. Mag. 37,357361.
Jones, J. B., and Segnit, E. R. (1971). “The nature of opal, I. Nomenclature and constituent phases,” J. Geol. Soc. Australia 18, 57–68.
Jones, J. B., and Segnit, E. R. (1972). “Genesis of cristobalite and tridymite at low temperatures,” J. Geol. Soc. Australia 18, 419–422.
Jones, J. B., Sanders, J. V., and Segnit, E. R. (1964). “Structure of opal,” Nature (London) 204,990991.
Kihara, K., Matsumoto, T., and Imamura, M. (1986a). “High-order thermal-motion tensor analysis of tridymite,” Z. Kristallogr. 172,3952.
Kihara, K., Matsumoto, T., and Imamura, M. (1986b). “Structural change of orthorhombic-I tridymite with temperature: A study based on second-order thermal-vibrational parameters,” Z. Kristallogr. 177,2738.
Klein, C., and Hurlbut, C. S., Jr. (1993). Manual of Mineralogy, 21st ed. (Wiley, New York), 681pp.
Langer, K., and Flörke, O. W. (1974). “Near infrared absorption spectra (4000–9000 cm −1) of opals and the role of water in these SiO 2·nH 2O minerals,” Fortsch. Miner. 52, 17–51.
Levin, I., and Ott, E. (1933). “X-ray study of opals, silica glass and silica gel,” Z. Kristallogr. 85,305318.
Mallard, E. (1890a). “Sur la Lussatite, nouvelle variete minerale cristallisee de silice,” Bull. Soc. Fr. Min. 13, 63–66.
Mallard, E. (1890b). “Sur la tridymite et la cristobalite,”Bull. Soc. Franc. Miner. 13, 161–180.
McClune, W. F. (1997). “The Powder Diffraction File,” International Centre for Diffraction Data, Newtown Square, PA.
Miles, W. J. (1994). “Crystalline silica analysis of Wyoming bentonite by X-ray diffraction after phosphoric acid digestion,” Anal. Chim. Acta 286,97105.
Miles, W. J., and Hamilton, R. D. (1991). “Detection and Measurement of Crystalline Silica in Minerals,” in Environmental Management for the 1990’s, edited by D. J. Lootens (SME, Littleton, CO), pp. 329–333.
Monroe, E. A., Sass, D. B., and Cole, S. H. (1969). “Stacking faults and polytypism in opal, SiO 2·nH 2O,Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr. 25,578580.
Nagase, T., and Akizuki, M. (1997). “Texture and structure of opal-CT and opal-C in volcanic rocks.” Can. Miner. 35, 947–958.
Nukui, A., and Nakazawa, H. (1980). “Polymorphism in tridymite,” J. Miner. Soc. Jpn. 14 (spec. Vol. 2), 364–386 (in Japanese).
Von Nieuwenkamp, W. (1935). “Die Kristallstruktur des tief-Cristobalits SiO 2,Z. Kristallogr. 92,8288.
Peacor, D. R. (1973). “High-temperature single crystal study of the cristobalite inversion,” Z. Kristallogr. 138,274298.
Pevear, D. R., Dethier, D. P., and Frank, D. (1982). “Clay minerals in the 1980 deposits from Mount St. Helens,” Clays Clay Miner. 30,241252.
Pluth, J. J., Smith, J. V., and Faber, J. Jr.(1985). “Crystal structure of low cristobalite at 10, 293 and 473 K: Variation of the framework geometry with temperature,” J. Appl. Phys. 57,10451049.
Rice, S. B., and Elzea, J. M. (1993). “Stacking disorder in the crystaline opals,” Clay Min. Soc. Abstracts with Program 137.
Sanders, J. V.(1975). “Microstructure and crystallinity of gem opals,” Am. Miner. 60,749757.
Sangster, A. G., and Hodson, M. J. (1986). “Silica in higher plants,” in Silicon Biochemistry, edited by D. Evered and M. O’Connor (Wiley, Chichester, UK), pp. 90–111.
Segnit, E. R., Anderson, C. A., and Jones, J. B. (1970). “A scanning microscope study of the morphology of opal,” Search. 1, 349–351.
Smelik, E. S., and Reeber, R. R. (1990). “A study of the thermal behavior of terrestrial tridymite by continuous X-ray diffraction,” Phys. Chem. Miner. 17,197206.
Smith, D. K., Tomiano, G. P., and Wright, A. C. (1998). “On the paracrystallinity of opal,” Proceedings of the XVII Conference on Applied Crystallography, Wisla, Poland, edited by H. Morawiec, and D. Stróz, Polish Academy of Sciences.
Van Valkenburg, A. Jr., and Buie, B. F.J. V.(1945). “Octahedral cristobalite with quartz paramorphs from Ellora Caves, Hyderabad State, India,” Am. Miner. 30,526535.
Wyckoff, R. W. G. (1925). “The crystal structure of the high temperature form of cristobalite (SiO 2),Am. J. Sci. 9,448459.
Ampian, S. G., and Vitra, R. L. (1992). Crystalline silica overview: Occurrence and analysis. Information Circular, IC-9317. U.S. Bur. Mines. Washington, DC, 27pp.
Arbey, F. (1979). “Les formes de la silice et l’identification des evaporites dans les formations silicifiees,” Bull. Cent. Rech. Explor. Prod. Elf Aquitaine. 4, 309–365.
Belonoshko, A. B., Dubrovinsky, L. S., and Dubrovinsky, N. A. Jr.(1996). “A new high-pressure silica phase obtained by molecular dynamics,” Am. Miner. 81,785788.
Bustillo, M. A., Fort, R., and Bustillo, M. (1993). “Specific surface area and ultramicroporosity in polymorphs of silica,” Eur. J. Mineral. 5,11951204.
Calvert, S. E. (1983). “Sedimentary geochemistry of silicon,” in Silicon geochemistry and biogeochemistry, edited by Aston (Academic, London).
Drees, L. R., Wilding, L. P., Smeck, N. E., and Senkayli, A. L. (1989). “Silica in soils: Quartz and disordered silica polymorphs,” in Minerals in soil environments, edited by J. P. Dixon (Soil Sci. Soc. Am. Madison, WI), pp. 913–975.
Elzea, J. M., Sprague, E. K., and Odom, I. E. (1991). “Characterization of low temperature silica polymorphs in calcium bentonites, sodium bentonites, and Fuller's earths by XRD, SEM/EDS and TEM,” (Abstr.) Clay Min. Soc. Abstracts with Program. 28, 43.
Fenner, C. N. (1913). “The stability relations of the silica minerals,” Am. J. Sci. 36,331384.
Flörke, O. W. (1959). “Regelungserscheinungen bei der paramorphen Unwandlung von SiO 2-Kristallen,” Z. Kristallogr. 112,126135.
Flörke, O. W., and Schneider, H. (1986). “Intergrowth relationships between the SiO 2-polymorphs quartz, cristobalite and tridymite in SiO 2-rich ceramic materials,” Ber. Dtsch. Keram. Ges. 63,368372.
Flörke, O. W., and Martin, B. (1993). “Silica modifications and products,” in Ullmann's Encyclopedia of Industrial Chemistry. Vol. A23, 583–598, 654–655 (VCH, New York).
Flörke, O. W., Martin, B., Benda, L., Paschen, S., Bergna, H. E., Roberts, W. I., Welsh, W. A., Ettlinger, M., Kerner, D., Kleinschmit, P., Meyer, J., Gies, H., and Schiffmann, D. (1993). Silica. Ullmann's Encyclopedia of Industrial Chemistry, VA23 (VCH, New York).
Garrison, R. E., Douglass, R. B., Pisciotto, K. E., Issacs, C. M., and Ingle, J. C. (Eds.) (1981). The Monterey Formation and related siliceous rocks of California, Soc. Econ. Paleontol. Min., Pacific Section, Los Angeles, 68, 307–323.
Gibbs, G. V., Downs, J. W., and Boissen, M. B., Jr. (1994). The Elusive Si-O Bond in Silica, Physical Behavior, Geochemistry, and Materials Applications, edited by P. J. Heaney, C. T. Prewitt, and G. V. Gibbs (Mineralogical Society of America, Washington, DC), pp. 369–402.
Harville, D., and Britton, A. (1994). “Identification and quantification of silica phases in the Monterey Formation using infrared spectroscopy,” A. A. A. P. Bull. 78, 664–665.
Heaney, P. J., and Banfield, J. A. (1995). “Structure and chemistry of silica, metal oxides and phosphates,” Health Effects of Mineral Dusts, edited by G. O. Guthrie and B. T. Mossman, Rev. Miner. 28, 185–233.
Heaney, P. J., Prewitt, C. T., and Gibbs, G. V. (Eds.) (1994). Silica, Physical Behavior, Geochemistry, and Materials Applications. Reviews in Mineralogy, Volume 29 (Mineralogical Society of America, Washington, DC), 606pp.
Iler, R. K. (1979). The Chemistry of Silica (Wiley, New York), pp. 21–28.
Odom, I. E., and Elzea, J. M. (1991). “Environmental aspects of silica minerals in clays and sediments,” Clay Miner. Soc. Abstr. with Program 28, 123.
Rey, T. (1966). “Ultrarotabsorption von AlPO 4 und SiO 2 in Abhangigkeit von Fehlordering und Temperatur,” Z. Kristallogr. 123,263314.
Smith, J. V., and Blackwell, C. S. (1984a). “Nuclear magnetic resonance of silica polymorphs,” Nature (London) 303,223225.
Smith, J. V., and Steele, I. M. (1984b). “Chemical substitution in silica polymorphs,” Neues. Jahrb. Min. Mon. 3, 137–144.
Sosman, R. B. (1965). The Phases of Silica (Rutgers University Press, New Brunswick, NJ).
Wahl, F. M., Grim, R. E., and Graf, R. B.(1961). “Phase transformations in silica as examined by continuous X-ray diffraction,” Am. Miner. 44,196208.
Wilding, L. P., Smeck, N. E., and Drees, L. R. (1977). “Silica in soils: quartz, cristobalite, tridymite and opal,” In Minerals in soil environments, edited by J. B. Dixon, S. B. Weed, J. A. Kittrick, M. H. Milford, and J. L. White (Soil Science Society of America, Madison, WI), pp. 471–552.
Barth, T. F. W. (1932). “The cristobalite structures: II Low-cristobalite,” Am. J. Sci. 24,97110.
Cruickshank-Banks, D. W., and Stevens, L. (1983). “The formation of cristobalite from diatomite—A dilatometric study,” Aust. Dental J. 28, 27–29.
Downs, R. A., and Palmer, D. C.(1994). “The pressure behaviour of α-cristobalite,” Am. Miner. 79, 9–14.
Eitel, W. (1957). “Structural anomalies in tridymite and cristobalite,” Am. Ceram. Soc. Bull. 57,142148.
Endell, J. (1948). “Rontgenographischer Nachweis Zwischenzustande be der Bildund Von Cristobaliteaus Klieselguhr beim Erhitzen, [X-ray Analysis Confirming the Existence of Intermediate Phases During Calcination of Diatomaceous-Earth],” J. Kolloidzachr. 11, 19–22.
Etchepare, J., Merian, M., and Kaplan, P. (1978). “Virational normal modes of SiO2. II Cristobalite and tridymite,” J. Chem. Phys. 68,15311537.
Flörke, O. W. (1955a). “Strukturanomalien bei Tridymit und Cristobalit,” Ber. Dtsch. Keram. Ges. 32,369381.
Flörke, O. W. (1955b). “Zur Frage des “High”-Cristobalit in Opalen, Bentoniten und Glaesern,” Neues Jahrb. Mineral. Monatasch. 10, 217–224.
Flörke, O. W. (1956). “Uber die Hoch-Tief Umwandlung und die thermische Ausdehnung von Cristobalit,” Ber. Dtsch. Keram. Ges. 33,319321.
Flörke, O. W. (1957). “Uber die Roentgen-Mineralanalyse und die thermische Ausdehnung von Cristobalit und Tridymit und uber die Zusammensetzung von Silikamassen,” Ber. Dtsch. Keram. Ges. 34,343353.
Flynn, P. T., Jr., Rosol, A. T., and Kinsala, S. D. (1991). “Cristobalite formation in diatomaceous earth—effects of time and temperature,” in Environmental Management for the 1990’s, edited by D. J. Lootens, W. M. Greenslade, and J. M. Barker (SME, Littleton, CO), pp. 367–371.
Hatch, D. M., and Ghose, S. (1991). “The α-β phase transition in cristobalite, SiO 2,Phys. Chem. Miner. 17,554562.
Hua, G. L., Welberry, T. R., Withers, R. L., and Thompson, J. G. (1983). “An electron diffraction and lattice-dynamical study of the diffuse scattering in β-cristobalite.J. Appl. Crystallogr. 21,458465.
Lally, J. S., Nord, G. L., Jr., Heuer, A, H., and Christie, J. M. (1978). “Transformation-induced defects in α-cristobalite,” Proc. 9th Int’l Congress on Electron Microscopy, Electron Microscopy 1, 476–477.
Laves, F. (1939). “Uber den Einfluß von Spannungen auf die Regelung von Quarz- und Cristobalit Kristallchen in Chalzedon, Quartzin, und Lussatit,” Naturwissenschaften 42,705717.
Leadbetter, A. J., and Wright, A. F. (1976). “The α-β transition in the cristobalite phases of SiO 2 and AlPO 4 I. X-ray studies,” Philos. Mag. 33,105112.
Leadbetter, A. J., Smith, T. W., and Wright, A. F. (1973). “Structure of high cristobalite,” Nature (London), Phys. Sci. 244,125126.
Lukesh, J.(1967). “Stability, lattice parameters and thermal expansion of α-cristobalite: A discussion,” Am. Miner. 52,541541.
Mason, B.(1972). “Lunar tridymite and cristobalite,” Am. Miner. 57,15301535.
Moehlman, R. S.(1935). “Quartz paramorphs after tridymite and cristobalite,” Am. Miner. 20,808810.
Murata, K. I., and Nakata, K. (1974). “Cristobalitic stage in the diagenesis of diatomaceous shale,” Science 184,567568.
Von Nieuwenkamp, W. (1935). “Die Kristallstruktur des tief-Cristobalits SiO 2,Z. Kristallogr. 92,8288.
Von Nieuwenkamp, W. (1937). “Uber die Struktur von hoch-Cristobalit,” Z. Kristallogr. 96,454458.
O’Keeffe, M., and Hyde, B. G. (1976). “Cristobalite and topologically-related structures,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 32,29232936.
Palmer, D. C., Hemley, R. J., and Prewitt, C. T.(1994). “Raman spectroscopic study of high-pressure phase transitions in cristobalite,” Phys. Chem. Miner. 21,481488.
Parise, J. B., Yeganeh-Haeri, A., Weidner, D. J., Jorgensen, J. D., and Saltzberg, M. A. (1994). “Pressure-induced phase transition and pressure dependence of crystal structure in low (α) cristobalite and Ca/Al-doped cristobalite,” J. Appl. Phys. 75,13611367.
Perotta, N. J., Grubbs, D. K., Martin, N. R., McKinstry, H. A., and Huang, C. Y. (1989). “Chemical stabilization of α-cristobalite,” J. Am. Chem. Soc. 61,441447.
Pevear, D. R., Williams, V. E., and Mustoe, G. E. (1980). “Kaolinite, smectite, and K-rectorite in bentonites: relation to coal rank at Tulameen, British Columbia,” Clays Clay Miner. 28,241254.
Phadke, A. V., and Kshirsagar, L. K. (1986). “Thermo-analysis of low cristobalite from Pune, Maharashtra, India: Paragenetic significance,” Z. Geol. Wiss. 14, 559–567.
Phillips, B. L., Thompson, J. G., Ziao, Y., and Kirkpatrick, R. J. (1993). “Constraints on the structure and dynamics of the α-cristobalite polymorphs of SiO 2 and AlPO 4 from 31P, 27Al and 29Si NMR spectroscopy to 770K,” Phys. Chem. Miner. 20,341352.
Richet, P., Bottinga, Y., Denielou, L., Petitet, J. P., and Tequi, C. (1982). “Thermodynamic properties of quartz, cristobalite and amorphous SiO 2: Drop calorimetry measurements between 1000 and 1800 K and a review from 0 to 2000 K,” Geochim. Cosmochim. Acta 48,26392658.
Schmahl, W. W. (1993). “Athermal transformation behavior and thermal hysteresis at the SiO 2-α/β-cristobalite phase transition,” Eur. J. Mineral. 5,377380.
Schmahl, W. W., Swainson, I. P., Dove, M. T., and Graeme-Barber, A. (1992). “Landau free energy and order parameter behaviour of the α/β phase transition in cristobalite,” Z. Kristallogr. 201,125145.
Schneider, H. (1986a). “Chemical composition of tridymite and cristobalite from volcanic and meteoritic rocks,” Neues Jahrb. Min. Mon. 10, 433–444.
Schneider, H. (1986b). “Chemical composition of tridymite and cristobalite from volcanic and meteoritic tocks,” Neues Jahrb. Mineral. Montasch. 433–444.
Schneider, H. and Majdic, A. (1984). “Iron incorporation in tridymite and cristobalite,” Neues Jahrb. Mineral. Monatsch. 559–568.
Siefert-Kraus, U. and Schneider, H. (1984). “Cation distribution between cristobalite, tridymite, and coexisting glass phases in used silica bricks,” Ceram. Int. 10, 135–142.
Spearing, D. R., Farnan, I., and Stebbins, J. F. (1992). “Dynamics of the α-β phase transitions in quartz and cristobalite as observed by in situ high-temperature 29Si and 17O NMR,” Phys. Chem. Miner. 19,307321.
Swainson, I. P., and Dove, M. T. (1993). “Low-frequency floppy modes in α-cristobalite,” Phys. Rev. Lett. 71,193196.
Thompson, A. B., and Wennemer, M. (1979). “Heat capacities and inversions in tridymite, cristobalite and tridymite-cristobalite mixed phases,” Am. Miner. 64,10181026.
Walker, R. F., Zerfoss, S., Holley, S. F., and Gross, L. J. (1958). “Temperature of the inversion in cristobalite,” J. Res. Natl. Bur. Stand. 61,251261.
Welberry, T. R., Hua, G. L., and Withers, R. L. (1989). “An optical transform and Monte Carlo study of the disorder in β-cristobalite,” J. Appl. Crystallogr. 22,8795.
Wilson, M. J., Russell, J. D., and Tate, J. M. (1974). “A new interpretation of the structure of disordered α-cristobalite,” Contr. Miner. Pet. 47, 1–6.
Withers, R. I., Thompson, J. G., and Welberry, T. R. (1989). “The structure and microstructure of α-cristobalite and its relationship to β-cristobalite,” Phys. Chem. Miner. 16,517523.
Wolfe, C. W.(1944). “Crystallography of Cristobalite from Ellora Caves, India,” Am. Miner. 29,536537.
Wright, A. F., and Leadbetter, A. J. (1975). “The structures of the β-cristobalite phases of SiO 2 and AlPO 4,Philos. Mag. 31,13911401.
Zhang, X., and Org, C. K. (1993). “Pressure-induced amorphization of β-cristobalite,” Phys. Rev. B 48,68656870.
Adams, S. I., Hawkes, G. E., and Curzon, E. H. (1991). “A solid state 29Si nuclear magnetic resonance study of opal and other hydrous silicas,” Am. Miner. 76,18631871.
Bartoli, F., Bittencourt-Rosa, D., Doirisse, M., Meyer, R., Philippy, R., and Samana, J. C. (1990). “The role of aluminum in the structure of Brazilian opals,” Eur. J. Mineral. 2,611619.
Blank, R. R., and Fosberg, M. A. (1991). “Duripans of Idaho: In situ alteration of eolian dust (loess) to an opal-A/X-ray amorphous phase,” Geoderma. 48, 131–149.
Boudreau, B. P. (1990). “Modelling early diagenesis of silica in non-mixed sediments,” Deep-Sea Research, Part A: Oceanographic Research Papers 37, 1543–1567.
Breese, R. O. Y. (1994). Diatomite in Industrial Minerals and Rocks, 6th ed., edited by D. D. Casr (DME, Littleton, CO), pp. 397–412.
Brunier, T. M. (1990). “Neutron scattering studies of amorphous materials,” Ph.D. Thesis, Univ. Reading, Whiteknights, Reading, UK.
Cady, S. L. (1994). “Microfibrous quartz and crystalline opaline silica varieties: Microstructural characterization by transmission electron microscopy and quantitative X-ray texture analysis,” Ph.D. Thesis, Univ. California, Berkeley, CA, 147pp.
Cady, S. L., and Wenk, H.-R. (1994). “Diagenetic microcrystalline opal varieties from the Monterey Formation, CA: HTREM study of the structures and phase transformation mechanisms,” (Abstr.) Geol. Soc. Am. Abstracts with Programs 26, A112.
Chester, R., and Elderfield, H. (1968). “The infrared determination of opal in siliceous deep-sea sediments,” Geochim. Cosmochim. Acta 32,11281140.
Curtil, L., and Murat, M. (1992). “Conditions de formation et microstructure des gels formes par dissolituon non congruente de l’opale dans les solutions basiques,” Compte Rendus des l;’Academie des Sciences, Serie 2, Mechanique, Physique, Chimie, Sciences de l’Univers, Sciences de la Terre. 315, 55–58.
Deelman, J. C. (1986). “Opal-CT in bamboo,” Neues Jahrb. Min. Mon. 9, 407–415.
Flörke, O. W., Flux, S., and Schroder, B. (1985). “Hyalith vim Steihwitzhugel bei Kulmain W’tiel des Egergrabens,” Neues. Jahrb. Min. Abh. 151, 87–97.
Flörke, O. W., Hollmann, R., Rad, U. V., and Rosch, H. (1976). “Intergrowth and twinning in Opal-CT lepispheres,” Contr. Miner. Pet. 58, 235–242.
Froelich, F. (1989). “Deep-sea boigenic silica: New structural and analytical data from infrared analysis—geological implications,” Terra Nova, 1, 267–273.
Gauthier, J. P. (1986). “Observation directe par microscopic electronique a transmission de diverse varieties d’opale: II Opal-synthetique,” J. Microsc. Spectrosc Elektron 11, 37–52.
Gauthier, J. P., and Bittencourt-Rosa, D. (1991). “Crystal-like organization in precious opal,” (Abstr) Sixth meeting of the European Union of Geosciences. Terra Abstracts 3, 404.
Goldberg, E. D. (1958). “Determination of opal in marine sediments,” J. Mar. Res. 17,178182.
Graetsch, H., and Ibel, K. (1997). “Small angle neutron scattering by opals,” Phys. Chem. Miner., 23 (in press).
Graetsch, H., and Topalovic-Dierdorf, T. (1996b). “MAS NMR spectra of hyalite from Gran Canaria,” Chemie Erde, 56, 387–391.
Graetsch, H., Flörke, O. W., and Ibel, K. (1991). “Neutronenkleinwinkelstreunung von Opalen und Chalzedon,” (abst.) Z. Kristallogr. 3,86.
Graetsch, H., Flörke, O. W., and Miehe, G. (1985). “The nature of water in chalcedonly and opal-C from Brazilian agate geodes,” Phys. Chem. Miner. 12,300306.
Graetsch, H., Gies, H., and Topalovic, I. (1994). “NMR, XRD, and IR study on microcrystalline opals,” Phys. Chem. Miner. 21,166175.
Graetsch, H., Mosset, A., and Gies, H. (1990). “XRD and 29Si MAS-NMR study on some non-crystalline silica minerals,” J. Non-Cryst. Solids 119,173180.
Greer, R. T. (1969). “Submicron structure of “amorphous” opal,” Nature (London) 224,11991200.
Guba, I. (1993). “Die aussergewoehnlichen Eigenschaften von Kascholong Opal aus einem neuentdeckten Vorkommen im Oman,” Deut. Gemmol. Ges. 42, 141–148.
Guthrie, G. D., Bish, D. L., Chipera, S. J., and Raymond, R. (1995). “Distribution of potentially hazardous phases in the subsurface at Yucca Mountain, Nevada,” Los Alamos Scientific Laboratory, Los Alamos, NM. Rept. No: LA-12573-MS. 41pp.
Ibel, K., and Wright, A. (1980). “An opal standard for very low momentum transfers in neutron small angle scattering,” ILL Internal Scientific Report 80IB45S.
Jones, J. B., Biddle, J., and Segnit, E. R. (1966). “Opal genesis,” Nature (London) 210,13531354.
Jones, R. L. (1969). “Determination of opal in soil by alkali dissolution analysis,” Soil Sci. Soc. Am. Proc. 33, 976–978.
Kato, K. (1983). “Ordering of opal-CT in diagenesis,” Geochem. J. 17, 87–93.
Khimicheva, N. V., Plyusnina, I. I., and Isirikyan, A. A. (1991a). “Adsorptive properties of the opal-quartz mineral series,” Moscow Univ. Geol. Bull. 46, 28–37 (in Russian).
Khimicheva, N. V., Plyusnina, I. I., and Isirikyan, A. A. (1991b). “Sorption properties of the minerals of the opal to quartz range,” Vestn. Mosk. Univ. Seriya 4 Geologiya Moscow, 33–44 (in Russian).
Kinnunen, K. A., and Ikonen, L. (1991). “Opal, a new hydromorphic precipitate type from gravel deposits in southern Finland,” Bull. Geol. Soc. Finland 63, 95–104.
Leinen, M. (1977). “A normative calculation technique for determining opal in deep-sea sediments,” Geochim. Cosmochim. Acta 41,671676.
Leinen, M. (1985). “Techniques for determining opal in deep-sea sediments: A comparison of radiolarian counts and X-ray diffraction data,” Marine Micropaleontology 9, 375–383.
Li, D., Bancroft, G. M., Kasrai, M., Fleet, M. E., Secco, R. A., Feng, X. H., Tan, K. H., and Yang, B. X.(1994). “X-ray absorption spectroscopy of silicon dioxide (SiO 2) polymorphs: The structural characterization of opal,” Am. Miner. 79,622632.
Mayerson, D. A., Dunkel, C. A., Piper, K. A., and Cousminer, H. L. (1995). “Identification and correlation of the Opal-CT/quartz phase transition in offshore Central California,” A. A. A. G. Bull. 79, 592.
Mitchell, R. S., and Tufts, S.(1973). “Wood opal—A tridymite-like mineral,” Am. Miner. 58,717720.
Mizota, C., Itoh, M., Kusakabe, M., and Noto, M. (1991). “Oxygen isotope ratios of opaline silica and plant opal in three recent volcanic ash soils,” Geoderma 50, 211–217.
Mueller, P. J., and Schneider, R. (1993). “An automated leaching method for the determination of opal in sediments and particulate matter,” Deep-Sea Research. Part I: Oceanographic Research Papers 40, 425–444.
Mueller, P. J., and Schneider, R. (1990). “Eine automatisierte Methode zur nasschemischen Bestimmung von Opal in Sinkstoffen und Sedimenten,” Nach. Deut. Geol. Ges. 43, 144.
Patalakha, Ye. I., Smirnov, A. V., and Korobkin, V. V. (1991). “Dehydration in opal as a result of disharmonious folding of siliceous strata,” Sovetskaya Geologiya. 1991, 93–95.
Pusey, P. N., van Megen, W., Bartlett, P., Ackerson, B. J., Rarity, J. G., and Underwood, S. M. (1989). “Structure of crystals of hard colloid spheres,” Phys. Rev. Lett. 63,27532756.
Radan, S., Seghudi, I., and Bunescu, C. (1992). “Opal lepispheres in hydrothermal alteration deposits from East Carpathians Neogene alteration zone,” Roumanian J. Min. 75, Supp. 1, 38.
Rice, S. B., Fruend, H., Huang, W. L., Clouse, J. A., and Issacs, C. M. (1995). “Application of Fourier transform infrared spectroscopy to silica diagenesis: The opal-A to opal-CT transformation,” J. Sed. Res. A 65, 639–647.
Ruland, W. (1971). “Small-angle scattering of two-phase systems: Determination and significance of systematic deviations from Porod's law,” J. Appl. Crystallogr. 4,7073.
Sanders, J. V. (1964). “Colour of precious opal,” Nature (London) 204,11511153.
Sanders, J. V. (1968). “Diffraction of light by opals,” Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr. 24,427434.
Tada, R., and Iijima, A. (1983). “Identification of mixtures of opalime silica phases and its implication for silica diagenesis,” In Siliceous Deposits in the Pacific Region, edited by A. Iijima, J. R. Hein, and R. Siever, (University of Tokyo Geological Institute, Tokyo, Japan), pp. 229–245.
Taijing, L., Zhang, X., Sunagawa, I., and Groves, G. W. (1995). “Nanometre scale textures in agate and Beltane opal,” Miner. Mag. 59,103109.
Taliaferro, N. L. (1935). “Some properties of opal,” Am. J. Sci. 30,450474.
Taylor, E. M., and Huckins, H. E. (1995). “Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at trenches 14 and 14D on the Bow Ridge fault at Exile Hill, Nye County, Nevada,” Open File Report, U.S. Goel. Surv. Rept. No.: OF 93-0477.
Vaniman, D. T., Ebinger, M. H., Bish, D. L., and Chipera, S. J. (1992). “Precipitation of calcite, dolomite, sepiolite and silica from evaporated carbonate and tuffaceous waters of southern Nevada, USA,” in Proc. 7th Int’l Symp, Water-Rock Interactions. Vol. 1. Low Temperature Environments, edited by Y. K. Kharaka, and A. S. Maest, U.S. Geol. Surv. Menlo Park, CA, pp. 687–691.
Ashworth, J. R. (1988). “Transformation mechanisms of tridymite to cristobalite studied by transmission electron microscopy,” Phys. Chem. Miner. 15,246251.
Ashworth, J. R. (1989). “Transmission electron microscopy of co-existing tridymite polymorphs,” Miner. Mag. 53,8997.
Baur, W. H. (1977). “Silicon-oxygen bond lengths, bridging angles Si-O-Si and synthetic low tridymite,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 33,26152619.
Blankenberg, H. J., Schoen, W., and Roesler, H. J. (1980). “Die Spurenelemente im Tridymit des Siderophyrs von Rittersgruen/Ertgebirge,” Chemie Erde 39, 98–90.
Buerger, M. J., and Lukesh, J. (1942). “The tridymite problem,” Science 95,2021.
Carpenter, M., and Wennemer, M.(1985). “Characterization of synthetic tridymites by transmission electron microscopy,” Am. Miner. 70,517528.
Cohen, L. H., and Klemment, W. K., Jr. (1980). “Tridymite: Effect of hydrostatic pressure to 6 kbar on temperatures of two rapidly reversible transitions,” Contrib. Miner. Pet. 71, 401–405.
De Dombal, R. F., and Carpenter, M. A. (1993). “High-temperature phase transitions in Steinbach tridymite,” Eur. J. Mineral. 5,607622.
Dollase, W. A. (1967). “The crystal structure at 220 °C of orthorhombic high tridymite from the Steinbach meteorite,” Acta Crystallogr. 23,617623.
Dollase, W. A., and Baur, W. H.(1976). “The superstructure of meteoric low tridymite solved by computer simulation,” Am. Miner. 61,971978.
Flörke, O. W. (1966). “Wachstum ind Verzwillingung von Tridymit,” Kristall und Technik, 1, 405–410.
Flörke, O. W., and Langer, K. (1972). “Hydrothermal recrystallization and transformation of tridymite,” Contr. Miner. Petrog. 36, 221–230.
Flörke, O. W., and Muller-vonmoos, M. (1971). “Displazive Tief-Hoch-Umwandlung von Tridymit,” Z. Kristallogr. 133,193302.
Flörke, O. W., and Nukui, A. (1988). “Strukturell Pathologie von Tridymiten,” Neues Jahr. Miner. Abb. 158, 175–182.
Friedlaender, C. G. J. (1970a). “Tridymite in the gangue of a Pb-Cu-Zn-occurrence,” Schseit. Mineral. Petrogr. Mitt. 50, 183–199.
Friedlaender, C. G. J. (1970b). “Entaxy of tridymite in the gangue of a Pb-Cu-Zn-occurrence,” Can. Mineral. 10, 704–709.
Goetz, W. (1962). “Intersuchungen am Tridymit des Siderophyrs von Grimuna in Sachsen,” Chemie Erde 22, 167–174.
Graetsch, H., and Flörke, O. W. (1991). “X-ray powder diffraction patterns and phase relationships of tridymite modifications,” Z. Kristallogr. 195,3148.
Graetsch, H., and Topalovic-Dierdorf, T. (1996). “29Si MAS NMR spectrum and superstructure of modulated tridymite L3-To(MX-1),” Eur. J. Mineral. 8,103113.
Gratten-Bellew, P. E. (1978). “Quartz-tridymite transition under hydrothermal conditions,” Expl. Mineral. 11, 129–139.
Hill, V. G., and Roy, R. (1958). “Silica structure studies. VI, On tridymite,” Trans. Brit. Cer. Soc. 57, 496–510.
Hoffmann, W. And Laves, F. (1964). “Zur Polytypie und Polytropie von Tridymit,” Naturwill. 51, 335.
Hoffmann, W., Kockmeyer, M., Lons, J., and Vach, C. (1983). “The transformation of monoclinic low-tridymite MC to a phase with an incommensurate superstructure,” Fortschr. Miner. 61, 96–98.
Imamura, M., and Matsumoto, T. (1980). “Change of X-ray diffraction pattern of tridymite by heating and cooling,” J. Mineral. Soc. Jpn. 14, 387–396 (in Japanese).
Kato, K., and Nukui, A. (1976). “Die Kristalstruktur des monoklinen Tief-Tridymits,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 32,24862491.
Kawai, K., Matsumoto, T., Kihara, K., and Sakurai, K. (1978). “The first finding of monoclinic tridymite in terrestrial volcanic rocks,” Miner. J. (Japan) 9, 231–235.
Kihara, K. (1977). “An orthorhombic superstructure of tridymite existing between about 105 and 180 °C,” Z. Kristallogr. 146,185203.
Kihara, K. (1978). “Thermal change in unit-cell dimensions, and a hexagonal structure of tridymite,” Z. Kristallogr. 148,237253.
Kihara, K. (1980). “On the split-atom model for hexagonal tridymite,” Z. Kristallogr. 152,95101.
Kihara, K. (1981). “Adenda and corrigendum for “On the split-atom model for hexagonal tridymite,” 157, 93.
Kim, Y. J., Xiao, Y., and Kirkpatrick, R. J. (1992). “TEM investigations of tridymite polymorphs,” (Abstr.) Trans. Am. Geophys. Union EOS 73, 620.
Konnert, J. H., and Appleman, D. E. (1978). “The crystal structure of low tridymite,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 34,391403.
Loens, J., and Hoffmann, W. (1987). “Zur Krustallstruktur der inkommensurablen Raumtemperaturphase des Tridymit,” Z. Kristallogr. 178,141143.
Nukui, A., and Flörke, O. W.(1987). “Three tridymite structural modifications and cristobalite intergrown in one crystal,” Am. Miner. 72,167169.
Nukui, A., Nakazawa, H., and Akao, M.(1978). “Thermal changes in monoclinic tridymite,” Am. Miner. 63,12521259.
Nukui, A., Yamamoto, A., and Nakazawa, H. (1979). “Non-integral phase in tridymite,” in Modulated Structures-1979, edited by J. M. Cowley, J. B. Cohen, M. B. Salamon, and B. J. Wuensch, Am. Inst. Phys. Conf. Proc. 53, 327–329.
Nukui, A., Yamaoka, S., and Nakazawa, H.(1980). “Pressure-induced phase transitions in tridymite,” Am. Miner. 65,12831286.
Ray, L. L. (1947). “Quartz paramorphs after tridymite from Colorado,” Am. Miner. 32,643646.
Sato, M. (1963a). “X-ray study of tridymite (1): On tridymite M and tridymite S,” Miner. J. (Japan) 4, 115–130.
Sato, M. (1963b). “X-ray study of tridymite (2): Structure of low tridymite,” Miner. J. (Japan) 4, 131–146.
Sato, M. (1964). “X-ray study of tridymite (3): Unit cell dimensions and phase transition of tridymite,” Type S. Miner. J. (Japan) 4, 215–225.
Schneider, H., and Floerke, O. W. (1982). “Microstructure, chemical composition, and structural state of tridymite,” Neues Jahrb. Min. Mon. 145, 280–290.
Schneider, H., and Floerke, O. W. (1986). “High-temperature transformation of tridymite single-crystals to cristobalite,” Z. Kristallogr. 175,165176.
Shadid, K. A., and Glasser, F. P. (1970). “Thermal properties of tridymite: 25 °C–300 °C,” J. Therm. Anal. 2,181190.
Tagai, T., and Sadanaga, R. (1972). “Tridymite features of its high-low transitions and structure of its 20-layer polytype,” Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr. 28,s121.
Tagai, T., Sadanaga, R., Takeuchi, Y., and Takeda, H. (1977). “Twinning of tridymite from the Steinbach meteorite,” Miner. J. (Japan) 8, 382–398.
Wennemer, M., and Thompson, A. B. (1984a). “Tridymite polymorphs and polytypes,” Schweiz Min. Petrogr. Mitt. 64, 335–353.
Wennemer, M., and Thompson, A. B. (1984b). “Ambient temperature phase transitions in synthetic tridymites,” Schweiz Min. Petrogr. Mitt. 64, 355–368.
Withers, R. L., Thompson, J. G., Xiao, Y., andKirkpatrick, R. J.(1994). “An Electron Diffraction Study of the Polymorphs of SiO 2-Tridymite,” Phys. Chem. Miner. 21,421433.
Xiao, Y., Kirkpatrick, R. J., and Kim, Y. J. (1993). “Structural phase transitions of tridymite: A 29Si MAS NMR investigation,” Am. Miner. 78,241244.
Hamilton, R. D., and Peletis, N. G. (1990). “The determination of quartz in perlite by X-ray diffraction,” Adv. X-Ray Anal. 23,493497.
Heaney, P. J., and Post, J. E. (1992). “The widespread distribution of a novel silica polymorph in microcrystalline quartz varieties,” Nature (London) 255,441443.
Hurst, V. J., Schroeder, P. A., and Styron, R. W. (1997). “Accurate quantification of quartz and other phases by powder X-ray diffractometry,” Anal. Chim. Acta 337,233252.
Kingma, K. J., and Hemley, R. J. (1994). “Raman spectroscopic study of microcrystalline silica,” Am. Miner. 79,269273.
Mallard, E. (1890). “Sur la Lussatite, nouvelle variete minerale cristallisee de silice,” Bull. Soc. Fr. Miner. 13, 63–66.
Midgley, H. G. (1951). “Chalcedony and flint,” Geol. Mag. 88, 179–184.
Miehe, G., Graetsch, H., and Florke, O. W. (1984). “Crystal structure and growth fabric of length-fast chalcedony,” Phys. Chem. Miner. 10,197199.
Renault, J., McKee, C., and Barker, J. (1991). “Quantitative X-ray Diffraction Analysis of Trace Quartz in Selected Mineral Products: Standardization II,” in Environmental Management in the 1990’s, edited by D. J. Lootens (SME, Littleton, CO), pp. 361–362.
Renault, J., McKee, C., and Barker, J. (1992). “Calibrating for X-ray analysis of trace quartz,” Adv. X-Ray Anal. 35,363373.
Seifert, H. (1966). Epitaxy of Macromolecules on Quartz Surfaces (Pergamon, New York).
Breese, R. O. Y., and Barker, J. M., “Perlite” in Industrial Minerals and Rocks, Sixth Ed., edited by D. D. Casr (DME, Littleton, CO), pp. 735–749.
Bridgeman, P. W. (1953). “Effects of high pressure on glass,” Am. J. Sci. 237,718.
Devine, R. A. (Ed.) (1988). The Physics and Technology of Amorphous SiO 2 (Plenum, New York).
Fanderlik, I. (Ed.) (1991). Silica Glass and its Applications (Elsevier, Amsterdam) 304pp.
Flörke, O. W. (1959). “Uber Kieselsaeurekristalle in Glaesern,” Glastechnische Berichte, 32, 1–10.
Galeener, F. L., and Wright, A. C. (1986). “The J. C. Phillips model for vitreous SiO 2: A critical appraisal,” Solid State Commun. 57,677682.
Grimley, D. I., Wright, A. C., and Sinclair, R. N. (1990). “Neutron scattering from vitreous silica,” J. Non-Cryst. Solids 119,4964.
Hosemann, R., Hentschel, M. P., Schmeisser, U., and Bruckner, R. (1986). “Structural model of vitreous silica based on microcrystalline principles,” J. Non-Cryst. Solids 83,223234.
Kubicki, J. D., and Lasaga, A. C. (1988). “Molecular dynamics simulations of SiO 2 melt and glass: Ionic and covalent models,” Am. Miner. 73,941955.
O’Keefe, J. A. (1984). “Natural glass,” J. Non-Cryst. Solids 67,117.
Pye, L. D., O’Keefe, J. A., and Frechette, V. D. (1984). Natural Glasses (North-Holland, Amsterdam), 662pp.
Sykes, D., and Kubicki, J. D. (1996). “Four-membered rings in silica and aluminosilicate glasses,” Am. Miner. 81,26652672.
Wright, A. C. (1994). “Neutron scattering from vitreous silica. V. The structure of vitreous silica: What have we learned from 60 years of diffraction studies?,” J. Non-Cryst. Solids 179,84115.
Wright, A. C., Desa, J. A. E., Weeks, R. A., Sinclair, R. N., and Bailey, D. K. (1984). “Neutron diffraction studies of natural glasses,” J. Non-Cryst. Solids 67,3544.
Wright, A. C., Bachra, B., Brunier, T. M., Sinclair, R. N., Gladden, L. F., and Portsmouth, R. L. (1992). “A neutron diffraction and MAS-NMR study of the structure of fast neutron irradiated vitreous silica,” J. Non-Cryst. Solids 150,6975.
Altree-Williams, S., Byrnes, J. G., and Jordan, B. (1981). “Amorphous surface and quantitative X-ray powder diffractometry,” Analyst (Cambridge, U.K.) 106,6975.
Bailey, D. A. (1947). “Conversion of silica on ignition,” J. Ind. Hyg. Toxic. 29, 242–249.
Bettermann, P., and Liebau, F. (1975). “The transformation of amorphous silica to crystalline silica under hydrothermal conditions,” Contrib. Min. Petrol. 53, 25–36.
Calacal, E. L., and Whittemore, O. J. (1987). “The scintering of diatomaite,” Am. Ceram. Soc. Bull. 66,790793.
Carr, R. M., and Fyfe, W. S. (1958). “Some observations on the crystallization of amorphous silica,” Am. Miner. 43,908916.
Correns, C. W., and Nagelschmidt, G. (1933). “Uber Faserbau und Optische Eigenshaften von Chalzedon,” Z. Kristallogr. 85,199213.
Crerar, D. A., Axtmann, E. V., and Axtmann, R. C. (1981). “Growth and ripening of silica polymers in aqueous solutions,” Geochim. Cosmochim. Acta 45, 1259–1266.
Graetsch, H., Floerke, O. W., and Miehe, G. (1987). “Structural defects in microcrystalline silica,” Phys. Chem. Miner. 14,249257.
Heaney, P. J. (1993). “A proposed mechanism for the growth of chalcedony,” Contr. Min. Pet. 115, 66–74.
Jordan, B., O’Connor, B. H., and Deyu, L. (1990). “Use of Rietveld pattern fitting to determine the weight fraction of crystalline material in natural low quartz specimens,” Powder Diffr. 5,6469.
Mozzi, R. L., and Warren, B. E. (1969). “The structure of vitreous silica,” J. Appl. Crystallogr. 2,164172.
Nakamura, T., Sameshina, K., Okunaga, K. et al. (1989). “Determine of amorphous phase in quartz powder by X-ray powder diffraction,” Powder Diffr. 4,913.
Rimstedt, J. D., and Barnes, H. L. (1980). “The kinetics of silica-water reactions,” Geochim. Cosmochim. Acta 44,16831699.
Stebbins, J. F., (1991). “NMR evidence for five-coordinated silicon in a silicate glass at atmospheric pressure,” Nature (London) 351,638639.
Williams, L. A., and Crerar, D. A. (1985). “Silica diagenesis, II: General mechanisms,” J. Sed. Petrol. 55, 312–321.
Williams, L. S., Parks, G. A., Crerar, D. A. (1985). “Silica diagenesis, I: Solubility controls,” J. Sed. Petrol. 55, 301–311.
Bartoli, F. (1985). “Crystallochemistry and surface properties of biogenic opal,” J. Soil Sci. 36, 335–350.
Bartoli, F., and Wilding, L. P. (1980). “Dissolution of biogenic opal as a function of its physical and chemical properties,” Soil Sci. Soc. Am. J. 44,873878.
Bendz, G., and Lindquist, I. (Eds.) (1977). Biochemistry of Silicon and Related Problems (Plenum, New York), 591pp.
Brewster, N. A. (1981). “The determination of biogenic opal in high latitude deep sea sediments,” (Abstr.) International conference on siliceous deposits in the Pacific region. Univ. Tokyo Tokyo, Jpn. 38.
Evered, D., and O’Connor, M. (Eds.) (1986). Silicon Biochemistry (Wiley, Chichester, UK), 264pp.
Gies, J. W. (1972). “Biogenic opaline silica in selected plant materials,” (Abstr.) Agronomy Abstracts, Madison, WI, p. 155.
Guthrie, G. D. J., and Heaney, P. J. (1995). “Mineralogical characteristics of the silica polymorphs in relation to their biological activity,” In Proc. 2nd Int’l Symp. Silica, Silicosis, and Cancer, edited by D. F. Goldsmith, G. R. Wagner, U. Saffioti, J. Rabovsky, and J. Leigh.
Hartwig, G., and Hench, L. L. (1972). “The epitaxy of poly-L-alanine on L-quartz and a glass-ceramic,” J. Biomed. Mater. Res. 6, 413–424.
Kaufman, P. B., Dayanandan, P., Takeoka, Y., Bigelow, W. C., Jones, J. D., and Iler, R. (1981). “Silica in shoots of higher plants,” in Silicon and Siliceous Structures in Biological Systems, edited by T. I. Simpson and B. E. Volcani (Springer-Verlag, New York), p. 409–449.
Koopmann, B. (1980). “Quantitative determination of silt sized biogenic silica in Atlantic deep-sea sediments,” (Abstr.) International Association of Sedimentologists, first European regional meeting. 30–33.
Kozin, F., Millstein, B., Mandel, G., and Mandel, N. (1982). “Silica induced membranolysis: A study of different structural forms of crystalline and amorphous silica and the effects of protein adsorption,” J. Colloid Interface Sci. 88,326337.
Langer, A. M. (1978). “Crystal faces and cleavage planes in quartz as templates in biological processes,” Q. Rev. Biophys. 11,543575.
Manein, D., Geiger, B., and Addadi, L. (1994). “Differential adhesion of cells to enantiomorphous crystal surfaces,” Science 263,14131416.
Mann, S., and Perry, C. C. (1986). “Structural aspects of biogenic silica,” in Silicon Biochemistry, edited by D. Evered, and M. O’Connor (Wiley, Chichester, UK), pp. 40–58.
Mortlock, R. A., and Froelich, P. N. (1989). “A simple method for the rapid determination of biogenic opal in pelagic marine sediments,” Deep-Sea Research. Part A: Oceanographic Research Papers. 36, 1415–1426.
Nash, T., Allison, A. C., and Harington, J. S. (1966). “Physico-chemical properties of silica in relation to toxicity,” Nature (London) 210,259261.
Pease, D. S., and Anderson, J. U. (1969). “Opal phytoliths in bouteloua eriopoda torr.-roots and soils,” Soil Sci. Soc. Am. Proc. 33, 321–322.
Weiss, A., and Herzog, A. (1977). “Isolation and characterization of a silicon-organic complex from plants,” in Biochemistry of Silicon and Related Problems, edited by G. Bendz and I. Lindquist (Plenum, New York).
Wilding, J. P., and Drees, L. R. (1974). “Contributions of forest opal and associated crystalline phases to fine silt and clay fractions of soils,” Clays Clay Miner. 22,295306.
Abrams, H. K. (1954). “Diatomaceous earth pneumoconiosis,” Am. J. Pub. Health. 44, 592–599.
Bagchi, N. (1992). “What makes silica toxic?” Brit. J. Indus. Med. 49, 163–166.
Brieger, M., and Gross, P. (1966). “On the theory of silicosis: I Coesite,” Arch. Environ. Health 13, 751–757.
Brieger, M., and Gross, P. (1967). “On the theory of silicosis: III Stishovite,” Arch. Environ. Health 15, 751–757.
Caldwell, D. M. (1958). “The coalescent lesion of diatomaceous earth pnumoconiosis,” Am. Rev. Tuberculosis. 77, 644–661.
Checkoway, H., Heyer, N. J., Demers, P. A., and Breslow, N. E. (1992). “A cohort mortality study of workers in the diatomaceous earth industry,” Unpublished final report from the Univ. Of Washington. School of Public Health and Community Medicine, Seattle, WA. Submitted to the International Diatomite Producers Assn. 133pp.
Craighead, J. E. (Chair) (1988). “Silicosis and silicate disease committee NOISH: Diseases associated with exposure to silica and nonfibrous silicate minerals,” Arch. Path. Lab. Med. 112, 673–720.
Craighead, J. E. (1992). “Do silica and asbestos cause lung cancer?” Arch. Pathol. Lab. Med. 116, 16–20.
Dunnom, D. D. (Ed.) (1981). “Health effects of synthetic silica particulates,” Am. Soc. Test. Mat. Philadelphia, PA. 226pp.
Ebbesen, P. (1991). “Fibrosis and tumour development in dust innoculated mice,” Eur. J. Cancer. Prev. 1, 39–41.
Fubini, B., Bolis, V., and Giamello, E. (1987). “The surface chemistry of crushed quartz dust in relation to its pathogenicity,” Inorg. Chim. Acta 138,193197.
Glenn, R. E. (1992). “Health effects of crystalline silica,” in 10th “Industrial Minerals” Int’l Congr., edited by J. B. Griffiths, Industrial Minerals Division of Metal Bulletin plc, May 1992, Surrey, UK, 112–119.
Goldsmith, D. F. (1994). “Silica exposure and pulmonary cancer,” in Epidemiology of Lung Cancer, edited by J. M. Samet (Dekker, New York), pp. 245–298.
Goldsmith, D. F., Winn, D. M., and Shy, C. M. (Eds.) (1986). Silica, Silicosis, and Cancer (Praeger, New York), 536pp.
Guthrie, G. D. Jr.(1992). “Biological effects of inhaled minerals,” Am. Miner. 77,225243.
Guthrie, G. D., Jr. (1995). “Mineralogical factors affect the biological activity of crystalline silica,” App. Occup. Environ. Hyg. 10, 1126–1131.
Guthrie, G. D. J., Jr., and Heaney, P. J. (1995). “Mineralogical characteristics of silica polymorphs in relation to their biological activities,” Scanda. J. Work, Environ. Health 21, 5–8.
Guthrie, G. D., Jr. and Mossman, B. T. (Eds.) (1993). Health Effects of Mineral Dusts. Reviews in Mineralogy, Volume 28, Mineralogical Society of America, Washington, DC, 584pp.
Hemenway, D. R., Absher, M., Landesman, M., Trombley, L., and Emerson, R. J. (1986). “Differential lung response following silicon dioxide polymorph aerosol exposure,” in Silica, Silicosis and Cancer, edited by D. F. Goldsmith, D. M. Winn, and C. M. Shy (Praeger, New York), pp. 105–116.
King, E. J., Mohanty, G. P., Harrison, C. V., et al. (1953). “The action of different forms of pure silica on the lungs of rats,” Br. J. Ind. Med. 19, 9–17.
Reiser, K. M., and Last, J. A. (1979). “Silicosis and fibrogenesis: Fact and artifact,” Toxicology 13, 51–72.
Rosner, D., and Markowitz, G. (1991). Deadly Dust, Silicosis, and the Politics of Occupational Disease in Twentieth Century America (Princeton University Press. Princeton, NJ), 229pp.
Ruhl, R., Schmucker, M., and Floerke, O. W. (1990). “Silikose druch nichtkristalline Kieselsaeure?,” Arbietsmed. Sozialmed Praventivmed 25, 8–15.
Saffioti, U. (1986). “The pathology induced by silica in relation to fibrogenesis and carcinogenesis,” in Silica, Silicosis, and Cancer edited by D. F. Goldsmith, D. M. Winn, and C. M. Shy (Praeger, New York), pp. 287–307.
Sax, N. I., and Lewis, R. J. (Eds.) (1988). Dangerous Properties of Industrial Materials, 7th ed., Vol. III (Van Nostrand Reinhold, New York) pp 3020–3023.
Selikoff, I. J. (1978). “Carcinogenic potential of silica compounds,” in Biochemistry of Silicon and Related Problems, edited by G. Benz and I. Lindquist (Eds.) (Plenum, New York).
Shi, X., Dalal, N. S., Hu, S. N. et al. (1989). “The chemical properties of silica particle surface in relation to silica-cell interactions,” J. Toxicol. Environ. Health 27,435454.
Vigliani, E. C., and Motlura, G. (1948). “Diatomaceous earth silicosis,” Br. J. Indus. Med. 5, 148–350.
Ball, R. A. (1977). “Natural or synthetic opal?” Aust. Gemmol. 13, 104–105.
Ball, R. A. (1978). “Identification of synthetic opal,” Aust. Gemmol. 13, 131–133.
Tombs, G. A. (1975). “Notes on identification of Gilson synthetic opals,” Aust. Gemmol. 12, 179–180.Regulatory
ACGIH (1984). Threshold limit values for chemical substances in the work environment adopted by the ACGIH conference for 1984-1985. Amer. Conf. Gov’t and Indust. Hygenists. Cincinnati, OH.
Branch of Industrial Minerals (1992). Crystalline Silica Primer. U.S. Bur. Mines Special Publ. 49p.
IARC (1987). IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans: Overall Evaluations of Carcinogenecity: An Updating of IARC Monographs 1-42, Supplement 7, World Health Organization, International Agency for Research on Cancer, Lyon, France, 440pp.
NIOSH (1974). Criteria for a Recommended Standard—Occupational exposure to crystalline silica. Department of Health, Education and Welfare, National Institutes for Occupational Safety and Health, Cinncinati OH.
Miles, W. J. (1990). “Mining industry responds to crystalline silica regulations,” Miner. Eng. 42, 345–348.
Miles, W. J., and Harben, P. W. (1991). “US crystalline silica regulations—Approaching the detection limits,” Ind. Miner. 291, 21–22,25,27.
Vu, V. T. (1995). “Regulatory approaches to reduce human health risks associated with exposures to mineral fibers,” Rev. Miner. 28, 545–554.
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Powder Diffraction
  • ISSN: 0885-7156
  • EISSN: 1945-7413
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