Classification of minerals

Minerals are usually classified into 9 groups which each comprise a different type of compound with a specific structure and/or composition. In the classification below each of these groups is mentioned together with some representatives of that group and in some cases its specific structure is discussed in more detail. Important minerals as for as ceramics are concerned, are placed in a box. 

Members of this group are the naturally occurring, at ordinary temperatures solid or liquid elements and their homogenous mixtures (alloys). The group is subdivided into two groups  

Lead sulphides are used as raw materials for lead oxides (e.g. Pb304) which, in their turn, are components of glazes. 

Ilia Simple halides halite NaCl, fluorite CaF2, chlorargyrite AgCl 

Illb Double halides ferrucite NaBF4 or NaF.BF3 (it is a mixed crystal) 

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A classification of mineral deposits has been proposed which recognizes the importance of concentration (or grade) as well as of geological occurrence. According to this classifica-... 

It is considered relevant to begin this presentation on flotation principles by drawing a reference to Figure 2.22 which quite comprehensively presents a summary of general classification of mineral processing separation methods. Present attention is focused on the... 

A.M. Gaudin Memorial Volume, M. C. Fuerstenau (ed.), AIME, 1 334 - 363 Povarennyk, A. S., 1972. Crystal Chemical Classification of Minerals (two vols.). New York Plenum Press... 

Povarennykh, A. S. 1972. Crystal Chemical Classification of Minerals. Plenum Press, New York. 

Povarennykh A. S., 1966, Kristallokhimicheskaya klassifikatsia mineralnykh vidov (Crys-tallochemical Classification of Mineral Spacies), Naukova Dumka, Kiev. 

MINERALOGY. The science of mineralogy is concerned with the formation, occurrence, properties, composition, and classification of minerals. Vnrinus definitions of a mineral have been proposed. Possibly, the most acceptable may be. "a naturally occurring inorganic substance, usually crystalline, possessing a relatively definite chemical composition and physical characteristics. It should be pointed out that some naturally formed organic substances, particularly of an economic resource nature, are sometimes classified as minerals. 

Table VI. SEM-AIA Classification of Mineral Matter in Pittsburgh No. 8 Coal Samples Obtained from TRW. The mineral phases are described by chemistry and area-equivalent diameter (in ym), expressed as weight percent of the total coal.

Following Lavoisier, chemists had a set of rules and a provisional list of elements to work with. Later, using Dalton s atomic theory and his laws of combining proportions, chemists were able to determine atomic weights and to arrive at molecular formulas indicating the nature and number of the atoms in a molecule. Molecules, the smallest part of a compound that possessed the chemical properties of that compound, could then be classified. Berzelius s classification of mineral compounds rested upon his discoveries about the electrochemical properties of atoms, an explanatory notion grafted onto Dalton s simple atomic theory. Chemists were able to establish research programs based... 

Dumitrescu and Kekedy used the FHDC procedure for the classification of mineral waters. Each sample was characterized by the analytical chemical data for eight major components CO2, HCO, Cl , Ca, Mg ", Fe, Na, and mineralization. Tentatively, classifications were made with a smaller number of components. The components present in greater concentration were successively omitted so as to investigate the possible influence on the classification of components present in smaller concentrations. Thus fuzzy hierarchical clustering was performed by considering successively only seven components (mineralization omitted), six constituents (mineralization and HCOj content omitted), or only five constituents (the previous and COj content omitted), respectively. With eight components the FHDC method yielded three clusters. To characterize the three distinct classes of water found, the total hardness (in German... 

For the Classification of Minerals , crystal-structure determinations improved the definitions of mineral species and varieties, assisted in the development of the concept of crystal structure types, helped to establish isotypic series and homeotypic and heterotypic groups, and pointed to the recognition of much broader crystallochemical relationships. The X-ray method appreciably simplified the generally unique characterization of a mineral species and led to a reduction in varieties and the discreditation of many minerals accepted up to that time, thereby eliminating countless superfluous mineral names . 

The chemical classification of minerals, begun by Berzelius and Rose, was developed into a comprehensive crystallographic-chemical classification over a period of about 100 years, especially by Naumann, Dana, Groth and Hintze, and has been published in well-known manuals and tables. The latest tabular summary, published by P. v. Groth and K. Mieleitner, appeared in 1921. The enormous progress in chemical crystallography since Laue s discovery (1912) requires that a fundamental revision of the cmrent system-atics should be undertaken. 

Table 3.3. Classification of Mineral Surface Adsorption Sites = Al, Fe = Mg, Fe)... 

Whereas soil scientists would classify clay by considering the particle size, a chemist describes it as part of the family of silicates and more precisely as hydrated silicates of aluminium. However, the classification of minerals with a stoichiometric formula does not reflect the complexity of their structure. In order to explain the properties of clay minerals in an adequate way, the coordination of silicon has to be described first, before looking at a long-range order in the crystals. 

Geochemical classification of mineral elements and interaction with reagents ... 

Altfaoufi a sharply defined classification of mineral waters is not possible, one which is useful, if not accurate, may be made, based upon the predominance of some constituent, or constituents, which impart to the water a well-defined therapeutic ue. A classification whi[Pg.109]

FIGURE 172. Chemical classification of minerals illustrated in Rene Haiiy, Traite de Mineralogie, Paris, 1801 (from the Othmer Library, CHF). 

The shape and symmetry of crystals attracted the attention of early crystallographers and, until the internal structure of crystals could be determined, was an important method of classification of minerals. The external shape, or habit, of a crystal is described as isometric (Uke a cube), prismatic (like a prism, often with six sides), tabular (like a rectangular tablet or thick plate), lathy (lath-like) or acicular (needle-Uke). An examination of the disposition of crystal faces, which reflected the symmetry of the crystal, led to an appreciation that all crystals could not only be allocated to one of the seven crystal systems but also to one of 32 crystal classes. 

Mineralogy The study of the formation, occurrence, properties, composition, and classification of minerals. 

Useful also is a genetic classification of minerals in coal, wherein they are classified as (1) detrital, (2) syngenetic, or (3) epigenetic. 

LIBS has been also successfully applied to the analysis of geochemical samples [1485]. The most accurate information can be obtained for the relative concentrations of different elements in a sample. This is important, for example, for the classification of minerals on earth or in meteroites when it is not clear whether two different samples come from the same source. Also for archeological samples the precise knowledge of elemental composition is very helpful for the exact dating and assignment. The applications of LIBS has benefitted from the use of fiber optics which allows remote sensing, where the laser and detection systems are far away... 

When the particle size is reduced, the yield of retained fraction is increased as a result of the greater adhesive forces this fact is used in classification of minerals such as barite, quartz, and feldspar. 

We can sum up our investigations of the history of chemists classification of minerals prior to Lavoisier by stating that this history confirms our analysis of the classif-... 

Although many structural classifications of minerals have already been proposed, none has focused on rare earth minerals. In view of the importance of the rare earths as natural resources as well as to earth sciences, we have started to review their structures as a series Crystal Structures of Rare Earth Minerals (abbreviated as CSRM) yearly updated in Rare Earths , the Journal of the Rare Earth Society of Japan (Miyawaki and Nakai 1987, 1988, 1989, 1990, 1991). We attempt in this series to provide the complete data necessary for understanding the crystal structures of the rare earth minerals. The present text is based on the CSRM, with permission of the society. In this text, we summarize our most up-to-date knowledge on the crystal structures of rare earth minerals. Thus, this will serve as a structural data base of rare earth minerals. We will continue to publish the CSRM, so that any new data, suggestions, corrections and criticisms are welcome and will be reflected in the next CSRM. Please send all correspondences to R.M. 

Minerals are most commonly classified on the basis of the presence of a major chemical component (i.e., anion or anionic complex) into several mineral classes such as, for instance, native elements, sulfides and sulfosalts, oxides, carbonates, sulfates, phosphates, silicates, etc. Today, there exist two main mineralogical classifications of minerals according to either... 

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