mineralogy

n., pl., -gies.

1. The study of minerals, including their distribution, identification, and properties.
2. A book or treatise on mineralogy.

mineralogical min'er·a·log'i·cal (-ər-ə-lŏj'ĭ-kəl) adj.
mineralogically min'er·a·log'i·cal·ly adv.
mineralogist min'er·al'o·gist n.

The science which concerns the study of natural inorganic substances, whether of terrestrial or extraterrestrial origin, called minerals. Mineralogy is a science that cannot be easily defined. It is most properly a branch of inorganic chemistry, but the discipline concentrates on the origin, description, and classification of minerals. See also Mineral.

Thus, four main categories may be considered: crystal chemistry (composition and atomic arrangement of minerals); paragenetic mineralogy (the study of mineral association and occurrence both in natural and synthetic systems); descriptive mineralogy (the study of the physical properties of minerals and the means for their identification); and taxonomic mineralogy (mineral classification, systematization, and nomenclature).

Crystal chemistry

This is the most vital aspect of mineralogy because it is the basis for the other studies. The fields of mineralogy, crystallography, inorganic chemistry, geochemistry, petrology, and geology are connected in the domain of crystal chemistry (Fig. 1).

Diagram showing the transmission of Information between mineralogy and some other sciences. Arrows Imply the direction of Information.

A particular mineral, called a mineral species, is defined on the basis of a specified chemical composition and a specified crystal structure (atomic arrangement). These two criteria provide almost sufficient knowledge for characterization of a mineral since in principle all other properties can be derived from them.

Crystalline substances, that is, periodic arrangements of matter in three dimensions, can be divided into six crystal systems: triclinic, monoclinic, orthorhombic, tetragonal, hexagonal (including the trigonal and rhombohedral subdivisions), and cubic. These crystal systems can be considered as structure cells, each of which contains a certain integral number of atoms of a substance. Figure 2 depicts these systems and offers the criteria for distinguishing them. See also Crystallography.

The cell shapes of the six crystal systems shown as their principal projections.

Any crystalline substance has a certain integral number of its essential chemical formula units loosely called molecules) in its structure cell. Thus, each unique atomic position in the structural unit can be occupied by a particular kind (or kinds) of atom(s). Consider the ideal cell formula (A_a)(B_b)…(P_p). Each of the parentheses specifies a unique atomic position. The capital letters specify the element present and the small subscripts the number of times it occurs in the cell. If the small subscripts have a factor in common, it is factored out and what remains is the formula unit. The ideal formula is further defined in terms of the atomic element which occurs in excess of 50 mole % within each of the parentheses. The structure type, along with the ideal formula unit, defines a mineral species.

This strict definition of a species is required since a particular mineral may have a range of compositions. The range of compositions is called a series. The ideal limiting compositions are called end members and each of the end members has a specific name.

Paragenetic mineralogy

Paragenetic mineralogy is the study of mineral paragenesis, or the association and order of crystallization of minerals. The problem may concern mineral association within a single hand specimen or may embrace a much larger region, such as an entire ore body, in which case many representative specimens are judiciously collected. This study usually accompanies the analysis of the general geological structures within and around the ore body, such as the bedding, folding, and faulting. Included among the important aspects of paragenetic mineralogy are ore mineralogy, the mineralogy of a sequence of phases crystallized from a parent magma, the sequence of minerals crystallized in a vein, and so forth. See also Geology; Petrology.

Mineral paragenesis is usually considered in relative time and the absolute difference in time between the oldest and youngest minerals is often not known. Absolute age differences can be obtained in some instances, for example, by lead isotope age dating of a sequence of crystallized lead-bearing minerals. See also Rock age determination.

Descriptive mineralogy

Mineral recognition directly by the senses is very subjective and requires considerable experience. Gross features of a mineral such as color, form, hardness, and specific gravity are important criteria for identification in the field where a well-equipped laboratory is usually not available. More objective criteria such as the optical properties and x-ray powder diffraction spectra of a mineral require specialized equipment, but the results are usually certain since these data are known for most mineral species and are extensively tabulated. Older methods such as fusibility, flame tests, and blowpipe analysis have been largely abandoned.

Taxonomic mineralogy

There are approximately 3000 distinct mineral species known to science, About 60 new mineral species are discovered each year. For a new species to be properly defined, the chemical analysis, structure cell and space group, crystal morphology, powder pattern, optical data, all physical properties, and paragenesis must be given as completely as possible.

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For more information on mineralogy, visit Britannica.com.

Observations on minerals in the New England and Virginia colonies appear in the writings of John Josselyn and other early-seventeenth-century travelers. In the mid-seventeenth century John Winthrop, son of the first governor of the Massachusetts Bay Colony, actively engaged in the search for and development of mineral deposits. His grandson, John Winthrop Jr., formed a notable mineral collection that was presented to the Royal Society of London in 1734 and later incorporated into the British Museum. Throughout the colonial period, questions about the nature and use of minerals and rocks and about the development of known mineral deposits were usually answered by sending specimens or trial shipments of ore abroad or by importing experts from Europe. The first professional study of mineralogy in America began after the Revolution—led by Adam Seybert, Gerard Troost, and the mineral chemist James Woodhouse, all of Philadelphia. The first mineral collections of scientific importance began to be acquired at about the same time. Most of the specimens were brought from Europe, chiefly by Americans traveling abroad for educational purposes and by immigrants of scientific or technological bent. It was the acquisition of these European collections, with their store of correctly identified and labeled material illustrating European textbooks, that provided the basis for American study instruction.

The formal teaching of mineralogy—the term then usually included earth history and other aspects of geology—began in American colleges shortly before 1800. Benjamin Waterhouse, a Rhode Island Quaker who had been trained in medicine and the natural sciences in Leyden and London, lectured on mineralogy and botany at Rhode Island College (later Brown University) in 1786 and at the medical school at Harvard between 1788 and 1812.

The first textbook on mineralogy written in the United States, Parker Cleaveland's Elementary Treatise on Mineralogy and Geology, was published in Boston in 1816. Cleaveland, a Harvard graduate of 1799, was self-taught in mineralogy. The work received good reviews in Europe and remained a standard text for many years. In 1837 James Dwight Dana of Yale brought out the System of Mineralogy, which became an international work of reference, reaching a sixth edition in 1892. Both of these books drew heavily on European works, especially those of the German Friedrich Mohs and of the French crystallographer R. J. Haüy.

The most rapid progress in mineralogy in the United States took place in the first three decades of the nineteenth century, as New England colleges sought to add the sciences to their theological and classical curricula. The leading figure was Benjamin Silliman, appointed professor of chemistry and natural science at Yale in 1802. Silliman was active as a teacher, editor, and public lecturer, rather than as a researcher. Among his students, Amos Eaton, Charles Upham Shepard, and Dana became important in the further development of the geological sciences.

The marked growth of the geological sciences in American colleges in the early nineteenth century was accompanied by the formation of numerous state and local academies, lyceums, and societies concerned with natural history. These organizations afforded public platforms from which such men as Silliman and Eaton and, later, Louis Agassiz spread scientific ideas. The Academy of Natural Sciences of Philadelphia, organized in 1812, was a leading factor; it began the publication of its journal in 1817 and of its proceedings in 1826. The Boston Society of Natural History, formed in 1830—the year the first state geological survey was begun, in Massachusetts—and the Lyceum of Natural History of New York, organized in 1817, also were important. The American Journal of Science and Arts, started by Silliman in 1818, published the bulk of American mineralogical contributions for the next five decades. (A forerunner, the American Mineralogical Journal, edited by Archibald Bruce of New York City, had published only four issues, 1810–1814.)

Toward the middle of the nineteenth century, courses in analytical chemistry, emphasizing ores, minerals, and agricultural materials, were introduced into many colleges and medical schools. Mineral chemistry and geochemistry developed strongly during the late 1800s, fostered especially by the U.S. Geological Survey, organized in 1879, and American work on minerals and rocks was outstanding in those fields. The publications of the U.S. Geological Survey and of the state geological surveys carried much descriptive mineralogical and petrographic material. Toward the end of the nineteenth century, as the organization and interests of science enlarged and specialized, the various academies and their attendant periodicals were joined and ultimately virtually supplanted by national and regional professional societies. The Mineralogical Society of America was founded in 1919 and continues today. The American Mineralogist, an independent journal first published in 1916, became its official journal.

The great private mineral collections, to which public museums and universities are deeply indebted, were developed during the last decades of the nineteenth century and the first decades of the twentieth century, a period coinciding with the major development of America's mineral resources and the accumulation of fortunes from mining in the West. Commercial dealing in mineral specimens, as by A. E. Foote of Philadelphia, developed on a large scale. Exhibits at national and international fairs, notably at the St. Louis World's Fair of 1904, also spread interest.

Crystallography, particularly in its theoretical aspects, did not attract much attention in the United States during the nineteenth century, when American interest in minerals was primarily concerned with chemical composition, occurrence, and use. It was not until the early twentieth century that advanced instruction and research in the formal aspects of crystallography became widespread. Charles Palache of Harvard was one of the leaders.

Over the course of the twentieth century, the boundaries of the discipline of mineralogy shifted with the change in economic and social priorities. As scientific interest in the traditional extractive resources—particularly iron ore and precious metals—declined in relation to research in oil exploration, nuclear waste storage, and earthquake and volcano prediction, mineralogy became an umbrella term for an array of highly technical fields, including petrology, crystallography, geochemistry, and geophysics.

Bibliography

Chandos, Michael Brown. Benjamin Silliman: A Life in the Young Republic. Princeton, N.J.: Princeton University Press, 1989.

Greene, John C., and John G. Burke. The Science of Minerals in the Age of Jefferson. Philadelphia: American Philosophical Society, 1978.

Oldroyd, David R. Sciences of the Earth: Studies in the History of Mineralogy and Geology. Brookfield, Vt.: Ashgate, 1998.

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Dansk (Danish)
n. - mineralogi

Nederlands (Dutch)
mineralogie

Français (French)
n. - minéralogie

Deutsch (German)
n. - Mineralogie

Ελληνική (Greek)
n. - μεταλλειολογία, ορυκτολογία

Italiano (Italian)
mineralogia

Português (Portuguese)
n. - mineralogia (f)

Русский (Russian)
минералогия

Español (Spanish)
n. - mineralogía

Svenska (Swedish)
n. - mineralogi

中文（简体）(Chinese (Simplified))
矿物学

中文（繁體）(Chinese (Traditional))
n. - 礦物學

한국어 (Korean)
n. - 광물학

日本語 (Japanese)
n. - 鉱物学

العربيه (Arabic)
‏(الاسم) علم المعادن‏

עברית (Hebrew)
n. - ‮תורת המחצבים (או המינרלים), מינרלוגיה‬

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