Clinochlore

clinochlore

[′klī·nə‚klȯr]

(mineralogy)

(Mg,Fe,Al)₃(Si,Al)₂O₅(OH)₄ Green mineral of the chlorite group, occurring in monoclinic crystals, in folia or scales, or massive.

Clinochlore

a mineral of the chlorite group; one of the layered aluminosilicates.

The approximate chemical composition of chlinochlore is

(Mg, Fe)_4.75 Al,_1.25 [Al,_1.25 Si_2.75 O₁₀] (OH)₈

The ratios of magnesium to aluminum and aluminum to silicon vary considerably, although clinochlore is primarily a magnesium-aluminum chlorite. The low-iron variety of clinochlore is known as leichtenbergite (colorless). Clinochlore containing admixtures of chromium is called kotschubeite (pinkish-violet).

Clinochlore crystallizes in the monoclinic system, forming small pseudohexagonal plumose crystals with good cleavage. Most often, clinochlore forms microplumose aggregates. Its color ranges from dark gray-green to light olive-green. Clinochlore is transparent in the form of thin laminae. Its hardness on the mineralogical scale is 2–2.5; its density varies between 2,610 and 2,780 kg per cu m. It is a rock-forming mineral in chlorite shales and occurs in other metamorphic rocks as well (appearing as a result of changes in pyroxenes, amphiboles, garnets, ferromagnesian mica). Clinochlore also exists in contact-meta-somatic rocks, such as skarns, and in modified secondary rocks in hydrothermal lodes. Clinochlore is very widely distributed in nature.

G. P. BARSANOV

Mentioned in ?

Chlorites

References in periodicals archive ?

Welch, "The effect of pressure upon hydrogen bonding in chlorite: a raman spectroscopic study of clinochlore to 26.5 GPa," American Mineralogist, vol.

Near-Infrared Spectroscopic Study of Chlorite Minerals

Castellanos and co-workers (personal communication) described in detail the characteristic mineral assemblages from reaction zones recognized in marbles, which include calcite + graphite [+ or -] quartz; calcite + diopside [+ or -] tremolite [+ or -] epidote-group minerals [+ or -] muscovite; calcite + wollastonite + quartz + garnet + diopside; calcite + dolomite + Ti-clinohumite + diopside + forsterite + clinochlore [+ or -] graphite; calcite + forsterite + tremolite; dolomite + calcite + clinochlore.

Ti-clinohumite in the Cienaga skarn-type mineralogy, Sierra Nevada de Santa Marta Massif (Colombia): occurrence and petrologic significance

The allochthonous minerals (chamosite, glauconite, chlorite and nacrite / clinochlore) could be due to the influx of shallow marine water into the passive continental depositional basin.

THE MINERALOGICAL AND PETROGRAPHICAL STUDIES OF THE LITHOFACIES OF THE HANGU FORMATION IN THE SALT RANGE, PUNJAB

* Q *, G * G **, KNA ** Cernuc Q *, Mi * Q *, F-Mi **, K **, Mi **, (central Bohemia, clinochlore in the rusty Velvary area) layer ** Py *** Table 2 A summary of results from mercury intrusion porosimetry.

Porosity changes induced by salt weathering of sandstones, Bohemian Cretaceous Basin, Czech Republic

amethysts from the Painter Farm, microclines from the Poorhouse quarry, clinochlore variety kammererite from the Scott mine, and others.

The mines and minerals of Chester County, Pennsylvania

Thus, various equilibria (e.g., E1 and E2 given in Table 2) could be calculated for T values between 250[degrees]C and 400[degrees]C considering the above components, the clinochlore (= [Mg.sub.5]Al[Al[Si.sub.3[[O.sub.10]][(OH).sub.8]) component in chlorite, the muscovite (KAl2[AlSi3O10](OH)2) component in potassic white mica as well as K-feldspar, quartz and [H.sub.2]O.

Condiciones P-T de metamorfismo de riolitas del Jurasico Superior en el cinturon de pliegues y mantos de Magallanes, Andes Patagonicos, Chile

Chrysotile (i.e., fibrous asbestos) is the most common mineral phase found in veins and shear zones crosscutting the serpentinite rocks (Figure 5), along with dolomite and trace amounts of clinochlore (i.e., sample R10).

Processes Governing Alkaline Groundwater Chemistry within a Fractured Rock (Ophiolitic Melange) Aquifer Underlying a Seasonally Inhabited Headwater Area in the Aladaglar Range (Adana, Turkey)

The intensity curves and stick pattern for all the three major minerals, Quartz, Muscovite and Clinochlore is given in Figure 2 and 3 respectively.

ENGINEERING GEOLOGICAL CHARACTERIZATION OF LAHORE SOIL, BASED ON GEOTECHNICAL TESTING AND MINERALOGICAL COMPOSITION USING X-RAY DIFFRACTION

Chlorite compositions are close to the ideal clinochlore composition ([Mg.sub.5][Al.sub.2][Si.sub.3][O.sub.10][(OH).sub.8]), with 3 ([+ or -] 0.1) Si, 2 (+ or -] 0.1) Al, and 5 ([+ or -]0.2) divalent ([R.sup.2+]) ions per unit formula (Appendix Table A3).

Very low- and low-grade metamorphism of mafic volcanic rocks of the Mira terrane (Avalonia), southeastern Cape Breton Island, Nova Scotia

The commonest species in sediments are the Mg- and [Fe.sup.2+] -rich trioctahedral chlorites, namely clinochlore and chamosite, and the Al-rich dioctahedral species, donbassite.

Phyllosilicates in the sediment-forming processes: weathering, erosion, transportation, and deposition

Lawrence County, New York and clinochlore from West-townr Chester County, Pennsylvania.