Abstract
Water at or near the earth’s surface plays an important role in the formation of some gem minerals. Surface water is capable of dissolving many minerals, particularly when provided a great deal of time to do so. As a result, it carries away components in solution that remain dissolved until, under appropriate conditions, new minerals are deposited. Precious opal and other gemstones form from surface water under special conditions that may include chemical reactions, cooling of waters previously heated by nearby molten rock, and evaporation. Rainwater, for example, combines with atmospheric carbon dioxide to produce carbonic acid, a weak natural acid. If such water seeps into the earth and encounters sulfides (such as pyrite, FeS2), sulfuric acid, a much stronger acid, is produced, which dissolves minerals, transports their chemical elements, and permeates other rocks to form new minerals.
Keywords
- South Wale
- Solid Silica
- Great Artesian Basin
- Water Seep
- Opal Deposit
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References
Australian Gem Industry Association. 1983. Australian Opals and Gemstones: Nature’s Own Fireworks. The Australian Gem Industry Ass’n. Lim., Sydney, pp. 2-11.
Bancroft, P. 1984. Gem and Crystal Treasures. Western Enterprises-Mineralogical Record, Fallbrook, CA, 488 pages.
Barnes, L. C., and I. J. Townsend. 1982. Opal, South Australia’s Gemstone. Geol. Survey of South Australia Handbook 5. D. J. Woolman, Eastwood, S. Australia. 157 pages.
Connah, T. H. 1966. A prospector’s guide to opal in western Queensland. Queensland Government Mining Journal 67:23–39.
Croll, I. C. H. 1950. Opal industry of Australia. Bureau of Mineral Resources Geology and Geophysics (Australia) Bull. 17:7–47.
Darragh, P. J., A. J. Gaskin, B. C. Terrell, and J. V. Sanders. 1966. Origin of precious opal. Nature 209:13–16
David, T. W. E. 1950. The Geology of the Commonwealth of Australia. I (of III): 482–487.
Epstein, D. 1988. Amethyst mining in Brazil. Gems & Gemology 24:214–228.
Gübelin, E. 1966. The ancient turquoise mines in Iran. Gems & Gemology 12:3–13.
Gurich, G. 1901. Edelopal und Opal: Pseudomorphosen von White Cliffs, Australia. Neues Jahrb. Mineralogie 14:472–483.
Hiern, M. N. 1967. Opal deposits at Coober Pedy. Q. geol. Notes, Geol. Surv. S. Aust. 13:6–7.
Hiern, M. N. 1967. Coober Pedy opal field; deposits in northern South Australia; Mintabie opal field; Myall Creek opal field. Min. Rev. (Adelaide) 122:5–22.
Holmes, G., S. R. Lishmund, and G. M. Oakes. 1982. A review of industrial minerals and rocks in New South Wales. Geological Survey of New South Wales. Dept. of Mineral Resources Bull. 30:199–202.
Jackson, C. F. V. 1902. The Opal Mining Industry and Distribution of Opal Deposits in Queens/and. Geological Survey of Queensland Publication 177.
Johns, R. K. 1968. Geology and mineral resources of the Andamooka-Torrens area. Bull. Geol. Surv. S. Aust. 41:103.
Jones, J. B., J. Biddle, and E. R. Segnit. 1966. Opal genesis. Nature 210:1353–1354.
Jones, J. B., and E. R. Segnit. 1966. The occurrence and formation of opal at Coober Pedy and Andamooka. Aust. Jour. Sci. 29:129–133.
Kalokerinos, A. 1971. Australian Precious Opal. Thomas Nelson (Aust.) Ltd., Melbourne.
Keeling, J. L. 1977. Opal in South Australia. Mineral Information Series, Department of Mines and Energy. Eastwood, S. Australia, 16 pages.
Leechman, F. 1961. The Opal Book. Ure Smith, Sydney. 263 pages.
MacNevin, A. A. and G. Holmes. 1977. Mineral Industry of New South Wales No. 18: Gemstones. 2d ed. New South Wales Geological Survey, Sydney.
Markham, N. C., and H. Basden. 1975. The Mineral Deposits of New South Wales. Geological Survey of New South Wales, Department of Mines, Sydney, Australia, 525–533.
Nixon, L. G. B. 1960. Andamooka opal field. Min. Rev. (Adelaide) 109: 13–23.
Pogue, J. E. 1919. The Turquois. 3d memoir, National Academy of Sciences 3.
Ralph, R. E. 1961. The White Cliffs Opal Field, New South Wales. New South Wales Department of Mines Technical Report 7 for 1959, Sydney, Australia, 7–18.
Sanders, J. V. 1964. Colour of precious opal. Nature 204:1151–1153.
Sanders, J. V. 1968. Diffraction of Light by Opals. Acta Crysta 424:427–436.
Scalisi, P., and D. Cook. 1983. Classic Mineral Localities of the World: Asia and Australia. Van Nostrand Rein-hold, New York. 226 pages.
Senior, B., D. McColl, B. Long, and R. Whiteley. 1977. The geology and magnetic characteristics of precious opal deposits, Southwest Queensland. Jour. Australian Geol. Geophysics 2:241–251.
Stone, D. M., and R. A. Butt. 1976. Australian Precious Opal. Perwinkle Books, Sydney.
Townsend, I. J. 1981. Discovery of early Cretaceous sediments at Mintabie opal field. Q. geol. Notes, Geol. Sur. S. Aust. 77:8–15.
Whiting, J. W., and R. E. Ralph. 1961. The Occurrence of Opal at Lightning Ridge and Grawin, with Geological Notes on County Finch. New South Wales Department of Mines Technical Report 6 for 1958, Sydney, Australia, 7–21.
Winton, L. J. 1925. The Coober Pedy (Stuart’s Range) opal field. South Australia Mining Review 42.
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Keller, P.C. (1990). Gemstones Formed from Surface Water: The Opals of Australia. In: Gemstones and Their Origins. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-6674-4_2
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DOI: https://doi.org/10.1007/978-1-4684-6674-4_2
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