Nomenclature of the amphibole supergroup

Hawthorne, Frank C.; Oberti, Roberta; Harlow, George E.; Maresch, Walter V.; Martin, Robert F.; Schumacher, John C.; Welch, Mark D.

doi:10.2138/am.2012.4276

Cited by 1,058 publications

(597 citation statements)

References 39 publications

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“…There are six fibrous mineral phases regulated by Law as "asbestos", five belonging to the amphibole family including tremolite asbestos, actinolite asbestos, anthophyllite asbestos, cummingtonite-grunerite asbestos (amosite), riebeckite asbestos (crocidolite), and one belonging to serpentine, which is chrysotile [1][2][3][4][5][6]. Certainly, chrysotile, crocidolite, and amosite have been the most intensively used for production of different kinds of materials.…”

Section: Introductionmentioning

confidence: 99%

Raman Micro-Spectroscopy Identifies Carbonaceous Particles Lying on the Surface of Crocidolite, Amosite, and Chrysotile Fibers

2018

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Micro-Raman spectroscopy has been applied on UICC (Union for International Cancer Control's) crocidolite and amosite from South Africa and on UICC chrysotile from Canada. Under Optical Microscope (OM), the surface of the fibers was often characterized by areas, micrometric in size, appearing dark. The laser beam was successively focused on areas of the same sample showing different optical contrasts. On the bright zones, Raman spectra peculiar for crocidolite, amosite or chrysotile were recorded. When dark areas were optically identified, the laser beam was addressed onto these regions and, in the Raman patterns, in addition to the bands produced by the mineral fiber, bands ascribing to substituted carbonaceous phases were observed. These bands were lying in the 4000-1100 cm −1 spectral range. On the basis of the shape of the bands and their relative intensities, suggestions about the order-disorder of the carbonaceous particles could be proposed, and they appeared more ordered on amosite than on crocidolite and chrysotile. From the exposed data, crocidolite and amosite fibers from South Africa, and chrysotile fibers from Canada, largely used in industry in the past, are characterized by many carbonaceous micrometric particles, lying on the fiber surfaces. Based on the noxiousness of the carbon particles on human health, their presence on asbestos fibers may play a role in increasing the carcinogenic effects of the analyzed fibrous minerals.

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Section: Introductionmentioning

confidence: 99%

Raman Micro-Spectroscopy Identifies Carbonaceous Particles Lying on the Surface of Crocidolite, Amosite, and Chrysotile Fibers

2018

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“…determines their mineralogical classification (Leake et al, 1997;Hawthorne et al, 2012). Many amphibole minerals form solid solution series, which are variations in chemical composition among two or more end members.…”

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Naturally Occurring Asbestos: Potential for Human Exposure, Southern Nevada, USA

Buck

Goossens

Metcalf

et al. 2013

Soil Science Society of America Journal

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“…Using Locock's (2014) amphibole spread sheet classification after the IMA 2012 report of Hawthorne et al (2012) (Table OSM5), amphiboles are classified as follows: amphiboles from Bt + Amp-granitoids are unzoned and compositionally similar to the ferro-hornblende cores of the amphiboles from Bt + Amp-Grt-granitoids, which instead have rims classified as ferro-pargasite, as is the case for the core of the rare amphibole inclusion in garnet (Fig. 8e).…”

Section: Mineral Chemistrymentioning

confidence: 99%

Magmatic garnet in the Cordilleran-type Galiléia granitoids of the Araçuaí belt (Brazil): Evidence for crystallization in the lower crust

Narduzzi

Farina

Stevens

et al. 2017

Lithos

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Magmatic garnet, together with epidote, is a rare mineral association in cordilleran-I-type granitoids and of special petrogenetic significance. The metaluminous to slightly peraluminous (ASI = 0.97-1.07) Galiléia batholith (Brazil) is a large (ca. 30,000 km 2 ), Neoproterozoic (ca. 632-570 Ma) weakly foliated calc-alkaline granitoid body, characterized by the widespread occurrence of garnet (grossular 25-43 mol%) and epidote (pistacite 9.3-22.7 mol%). Field, petrographic and mineral chemical evidence indicates that garnet, epidote, biotite as well as white mica crystals (low-Si phengite), are magmatic. There is no difference in bulk rock major and trace element composition between the Galiléia granitoids and other garnet-free cordilleran-type granitoids worldwide. This evidence strongly suggests that the origin of the uncommon garnet + epidote parageneses is related to the conditions of magma crystallization, such as pressure, temperature and water content. Comparison between the mineral assemblages and mineral compositions from this study and those recorded in crystallization experiments on metaluminous calc-alkaline magmas, as well as within garnet-bearing metaluminous volcanic rocks and granitoids, indicates that the supersolidus coexistence of grossular-rich garnet, epidote and white mica is consistent with magma crystallization at pressures greater than 0.8 GPa (above 25 km depth) and at temperatures below 700°C, i.e. near the water saturated solidus. Furthermore, resorption textures around garnet (plagioclase ± quartz coronas) and epidote suggest that these minerals have been partially consumed prior to complete crystallization. These findings demonstrate that at 630 Ma the crust underneath the Araçuaí Orogen was already at least 25-30 km thick and relatively cool. However, this contrasts with the marked high heat flow registered from the neighbour Carlos Chagas Batholith located 50 km to the east. In fact such granitoids record granulite-facies metamorphism at the same pressure and time (ca. 570 Ma) of Galiléia granitoids crystallization. Thus, a more suitable geodynamic scenario is required in order to explain these two contrasting thermal regimes within the same orogen. Eventually, field, petrographic and mineral chemical analogies with similar garnet-bearing granitoids located in the fore-arc settings of the British Columbia subduction zone, possibly imply that the Galiléia granitoids represent "rare" garnet-and epidote-bearing metaluminous Cordilleran-Itype granites which can only form in a fore-arc setting.

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Nomenclature of the amphibole supergroup

Cited by 1,058 publications

References 39 publications

Raman Micro-Spectroscopy Identifies Carbonaceous Particles Lying on the Surface of Crocidolite, Amosite, and Chrysotile Fibers

Raman Micro-Spectroscopy Identifies Carbonaceous Particles Lying on the Surface of Crocidolite, Amosite, and Chrysotile Fibers

Naturally Occurring Asbestos: Potential for Human Exposure, Southern Nevada, USA

Magmatic garnet in the Cordilleran-type Galiléia granitoids of the Araçuaí belt (Brazil): Evidence for crystallization in the lower crust

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