Chlorite minerals

Flint clays and other related rocks are another potential lithium source. These are high alumina clays that are composed largely of we11-crysta11i2ed kaolinite [1318-74-1] and are used for the manufacture of refractories (qv). The lithium content ranges from <100 to 5000 ppm. Deposits occur in many states, including Missouri, Peimsylvania, and Ohio. Lithium (at ca 1.3%) is present in a chlorite mineral that is similar to cookeite [1302-92-7]. High lithium contents may be the reason why some deposits are unsatisfactory for refractory use. 

Katsumoto, N. and Shirozu, H. (1973) Chlorite minerals associated with the gypsum deposits of the Wanibuchi mine, Shimane Prefecture. Sci. Rep. Dep. Geol. Kyushu U., 11, 231-241 (in Japanese). 

Shirozu, H. (1969) Chlorite minerals. In Clay of Japan. Tokyo Japan Geol. Survey, pp. 64-67. 

Shirozu, H. (1969) Chlorite minerals. In Editorial subcommittee for the Clays of Japan Organizing Committee (eds.). The Clays of Japan. Proc. 1969 Int. Clay Conf., Geol. Surv. Japan, pp. 183-194. 

Fig. 2.13 The 1 1 and 2 1 layer arrangements in the sheet structure minerals and the (010) view of the structures of the serpentine, clay, talc, pyrophyllite, mica, and chlorite minerals. X = layer charge per formula unit. [From Bailey (1980), Fig 1.1, p. 3 Fig 1.2, p. 6.1...

Fig. 4. Relation between clays and coffinite at Cigar Lake (a, b, c, e and f) and at Oklo (d) (a) to (d) uranium progressively invades the clay phase until complete replacement in (d) (e) coffinite replacing a chlorite mineral (precipitation of coffinite around a chlorite flake) (f) map of the distribution of uranium corresponding to the rectangle in (e). (C = clay mineral Co = coffinite.)...

Because the compositions are basic, the expanding minerals are trioctahedral and they are apparently associated in all facies with chlorite. The occurrence of a regularly interstratified montmorillonite (saponite) -chlorite mineral, corrensite, is typified by an association with calcic zeolites and albite. Temperature measurement in the "hydrothermal" sequences at several hundred meters depth indicate that the ordered, mixed layered mineral succeeds a fully expandable phase between 150-200 C and this ordered phase remains present to about 280°C. In this interval calcium zeolites disappear, being apparently replaced by prehnite. The higher temperature assemblage above corrensite stability typically contains chlorite and epidote. 

VEN1ALE (F.) and VAN DER MAREL (H.U.), 1963. An interstratified saponite-swelling chlorite mineral as a weathering product of Lizardite rock from St. Margherita Staffora (Pavia Province), Italy. Beitr dge Min. Petr. 9, 198-245. 

Fig. 13-20.—The sequence of layers normal to the cleavage plane of the chlorite minerals, showing the alternation of mica layers such as [Mg3AlSis-Oio(OH)2] with charged brucitelike layers [MgaAl-(OH),]+.

Several of the iron-rich clays as well as an amesite have a larger R3+ value than that allowed for the biotites. Nelson and Roy (1958) were not able to synthesize a 1 1 (amesite) or a 2 2 (chlorite) mineral with more than 33% A1 substituting for Mg (Mg8Al4) in the octahedral sheet. However, if the analyses in Fig. 24 are correct, it appears that when Fe2+ rather than the smaller Mg is the dominant cation in the octahedral sheet, up to 50% R3+ can occur in the octahedral position. Foster s (1960) biotite data show a similar relation. 

Brindley, G.W., 1961a. Chlorite minerals. In G. Brown (Editor), The X-ray Identification and Crystal Structures of Clay Minerals. London Mineral. Soc., London, pp. 242-296. 

In general, the minerals now identified as chamosite are found in iron ore bodies of sedimentary origin (e.g., Maynard, 1986 Fernandez and Moro, 1998 Wiewora et al, 1998 Kim and Lee, 2000). Chamosite associated with iron oxides appears to follow a compositional trend from iron oxides plus kaolinite to chlorite, as indicated in Figure 8, using the data of Velde (1989). The recombination of iron oxide in the presence of kaolinite gives an aluminous, ferrous mineral, chamosite. This mineral is formed under burial conditions where ferric iron oxide is reduced to feiTous iron which is rapidly incorporated into a 7 A chlorite mineral. Both chamosite and berthierine result from the reduction of ferric iron to ferrous iron. 

The last group, (d), of structures in which positively and negatively charged layers alternate, is also a small one and includes the chlorite minerals (p. 824) and some hydroxyhalides such as [Na4Mg2Cli2] [Mg7Al4(OH)2 2] (p- 212). 

The structural unit of a chlorite mineral consists of a 2 1 layer with the negative charge balanced by a positively charged octahedral hydroxide sheet in the interlayer. Two different types of octahedral layers are therefore present, one within the 2 1 TOT layers and the other between them. In di- and trioctahedral chlorites, both types of octahedral sheets are di- or trioctahedral, respectively. Di,trioctahe-dral chlorites have 2 1 dioctahedral layers and trioctahedral interlayers (the reverse mineral is not known). A detailed discussion of specific chlorite minerals can be found in Ref 12. Refer to Figure 2 for the [010] crystallographic view of a chlorite and to Table 2 for the composition of clinochlore, one chlorite mineral. 

Grissom (1986) mentions the presence of chlorite minerals in green earth q.v.) pigments. 

Chlorite minerals have been identified in green earfti (. v.) pigments rich in glauconite, together with members of the clay minerals group, in particular iUite and montmorillonite ((qq.v.) Grissom, 1986). 

Sheet silicates (phyllosihcates), as the name suggests, form a plane of silica tetrahedra, each linked to another at three corners. This structure is often echoed clearly in the mineral, producing minerals of high aspect ratio, with a well-developed cleavage. The clay minerals, chlorite minerals and micas are sheet sihcates (qq.v.). 

The structural unit of a chlorite mineral consists of a 2 1 layer with the negative... 

Thermal dilatometric curves obtained for six bricks extruded from different raw materials are shown in Fig. Curves for those manufactured from similar raw materials, but made by different forming methods, i.e., soft mud, dry press, and stiff extrusion, are shown in Fig. 23. From room temperature up to 500°C, the dimensional change is approximately linear and is due to thermal expansion. The abrupt increase in expansion (500-800°C) is due to phenomena such as quartz inversion, exfoliation of the illitic, and chloritic minerals due to dehydroxylation, and, possibly, the escape of CO2 under pressure. 

Alietti, A., 1958. Some interstratified clay minerals of the Taro Valley. Clay Min. Bull 3 207-211. Andrew, R. W., M. L. Jackson, and K. Wada, 1960. Intersaltation as a technique for differentiation of kaolinite from chlorite minerals by X-ray diffraction. Proc. Soil Sci. Soc. Am. 24 422-424. Bailey, S. W., and B. E. Brown, 1962. Chlorite polytypism. I. Regular and semirandom one-layer structures. Am. Mineral 47 819-850. 

Chlorite minerals. In The X-Ray Identification and Crystal Structures of Clay Minerals. 

Simonne Caillere, and S. Henin, 1950. Nouvel essai de classification des chlorites. Mineral... 

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