Minerals and Rocks

The chemical resources of early humans were limited to the metals and compounds on the earth s surface. A few metals (e.g., copper, silver, and gold) were found uncombined (native) in nature, so they have been available for many centuries. It is believed that the iron first used may have been found as uncombined iron that had reached the earth in the form of meteorites. In contrast, elements such as fluorine and sodium are produced by electrochemical reactions, and they have been available a much shorter time. 

The lithosphere consists primarily of rocks and minerals. Some of the important classes of metal compounds found in the lithosphere are oxides, sulfides, silicates, phosphates, and carbonates. The atmosphere surrounding the earth contains oxygen, so several metals such as iron, aluminum, tin, magnesium, and chromium are found in nature as the oxides. Sulfur is found in many places in the earth s crust (particularly in regions where there is volcanic activity), so some metals are found combined with sulfur as metal sulfides. Metals found as sulfides include copper, silver, nickel, mercury, zinc, and lead. A few metals, especially sodium, potassium, and magnesium, are found as the chlorides. Several carbonates and phosphates occur in the lithosphere, and calcium carbonate and calcium phosphate are particularly important minerals. 

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Calcium. Calcium is the fifth most abundant element in the earth s cmst. There is no foreseeable lack of this resource as it is virtually unlimited. Primary sources of calcium are lime materials and gypsum, generally classified as soil amendments (see Calcium compounds). Among the more important calcium amendments are blast furnace slag, calcitic limestone, gypsum, hydrated lime, and precipitated lime. Fertilizers that carry calcium are calcium cyanamide, calcium nitrate, phosphate rock, and superphosphates. In addition, there are several organic carriers of calcium. Calcium is widely distributed in nature as calcium carbonate, chalk, marble, gypsum, fluorspar, phosphate rock, and other rocks and minerals. 

Rubidium-87 emits beta-particles and decomposes to strontium. The age of some rocks and minerals can be measured by the determination of the ratio of the mbidium isotope to the strontium isotope (see Radioisotopes). The technique has also been studied in dating human artifacts. Rubidium has also been used in photoelectric cells. Rubidium compounds act as catalysts in some organic reactions, although the use is mainly restricted to that of a cocatalyst. 

F. H. Pough, Rocks and Minerals Houghton Mifflin Co., Boston, Mass., 1988. 

Grady, D.E. (1977), Processes Occurring on Shock Wave Compression of Rocks and Minerals, in High Pressure Research Applications in Geophysics (edited by Manghnani M.H. and S. Akimoto), Academic Press, New York, pp. 389-438. 

More than 90% of the rocks and minerals found in the earth s crust are silicates, which are essentially ionic Typically the anion has a network covalent structure in which Si044-tetrahedra are bonded to one another in one, two, or three dimensions. The structure shown at the left of Figure 9.15 (p. 243), where the anion is a one-dimensional infinite chain, is typical of fibrous minerals such as diopside, CaSi03 - MgSi03. Asbestos has a related structure in which two chains are linked together to form a double strand. 

Clayton, J. L. (1986). An estimate of plagioclase weathering rate in the Idaho batholith based upon geochemical transport rates. In "Rates of Chemical Weathering of Rocks and Minerals" (S. M. Coleman and D. P. Dethier, eds). Chap. 19, pp. 453-466. Academic Press, New York. 

Vol. 27. Rock and Mineral Analysis. Second Edition. By Wesley M. Johnson and John A. Maxwell... 

Abbey S (1980) Studies in Standard Samples for use in the general analysis of Silicate Rocks and Minerals, Part 6 1979 Edition of Usable Values. Pap - Geol Surv Can Paper 80-14. 

Further advances in the interpretation of mineral data could come from in situ analyses (unfortunately only possible presently on U-Th rich accessory minerals like zircon), or from detailed studies of particularly large phenocrysts, whose successive growth zones could be sampled (e g., through microdrillings) and analyzed. Ra measurements in such crystals could allow a direct determination of their growth rates. A systematic study of successive, well-dated eruptions of a given volcano, combining U-series measurements in both whole rocks and minerals, should also help with the interpretation of mineral data. 

Mottana, A., R. Crespi, and G. Liborio (1978), Simon and Schuster s Guide to Rocks and Minerals, Simon and Schuster, New York. 

Vol. 21 Reilctance Spectroscopy. By Wesley Wm.Wendlandt and Harry G. Hecht Vol. 22 The Analytical Toxicology of Industrial Inorganic Poisons. By the late Morris B. Jacobs Vol. 23 The Formation and Properties of Precipitates. By Alan G.Walton Vol. 24 Kinetics in Analytical Chemistry. By Harry B. Mark, Jr. and Garry A. Rechnitz Vol. 25 Atomic Absorption Spectroscopy. Second Edition. By Morris Slavin Vol. 26 Characterization of Organometallic Compounds (in two parts). Edited by Minoru Tsutsui Vol. 27 Rock and Mineral Analysis. Second Edition. By Wesley M. Johnson and John A. Maxwell Vol. 28 The Analytical Chemistry of Nitrogen and Its Compounds (in two parts). Edited by C. A. Streuli and Philip R.Averell... 

Because of the simplicity of doing scratch tests, hardness has been an important diagnostic tool for mineralogists and prospectors by helping them to identify various rocks and minerals. 

A fascinating guide into the history and modern uses of the inert gases, including their new, little-known ability to combine.) bottley, e. p., Rocks and Minerals, G. P. Putnams Sons, New York, 1969 (An advanced book, with beautifully colored pictures of elements and compounds as they are found in nature.) fisher, douglas a., Steel from the Iron Age to the Space Age, Harper and Row, New York, Evanston, and London, 1967 (The story of steel, and the men who made it.) newcomb, ellsworth and kenny, hugh, Miracle Metals, G. P. Putnam s Sons, New York, 1962... 

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