China
Africa
Explore chapters and articles related to this topic
List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
Asbestos, a naturally occurring fibrous mineral, is widespread in nature. Asbestos is non-combustible, resistant to heat, and features a low conductivity and is insoluble in water. Asbestos is classified into two groups: (i) serpentine and (ii) amphibole. The serpentine group includes: (i) chrysotile: molecular formula: Mg3Si2O5(OH)4; and (ii) crocidolite: molecular formula: Na2Fe2(Fe,Mg)3Si8O22(OH)2. The amphibole group includes (i) amosite: molecular formula: Na2Fe2(Fe,Mg)3Si8O22(OH)2; (ii) anthophyllite: molecular formula: Mg7Si8O22(OH)2; (iii) tremolite: molecular formula: Ca2Mg5Si8O22(OH)2; and (iv) actinolite: molecular formula: Ca2(Mg,Fe)5Si8O22(OH)2.
Asbestos Identification and Abatement
Published in Benjamin Alter, Environmental Consulting Fundamentals, 2019
There are six known asbestos minerals, as follows: Chrysotile, a white or greenish-colored mineral, was the most commonly used asbestiform in the United States and the only serpentine asbestiform (see Figure 15.1).Amosite, also known as “brown asbestos,” is an amphibole asbestiform that derives its name from the asbestos mines of South Africa.Crocidolite, also known as “blue asbestos,” is an amphibole asbestiform that was mainly mined in South Africa and Australia, and had limited usage in the United States.Anthophyllite is an amphibole asbestiform that has excellent resistance to chemicals and heat. It was primarily used in the United States in decorative and acoustical material.Tremolite is a white to yellow-colored amphibole asbestiform that has a major ingredient in industrial and commercial talc. There is also a non-asbestiform type of tremolite.Actinolite, an amphibole asbestiform that is greenish to white in color, has poor resistance to chemicals and had limited commercial usage. It may be found in commercial and industrial talcs.
Gold deposits of the Ukraine: Mineralogy and Geochemistry
Published in Adam Piestrzyński, Mineral Deposits at the Beginning of the 21st Century, 2001
V.M. Zagnitko, V.M. Kvasnytsya, A.Y. Parfenova, V.S. Monakhov, V.V. Sukach
The central zones of these metasomatites have a quartz-talk-carbonate-amphibole (tremolite - actinolite) ± talc composition, which changes into quartz-chlorite, chlorite-biotite or carbonate-chlorite metasomatic schists, commonly with porphyroblastic amphibole grains of different orientation, presented by actinolitic and magnesian hornblende. The lower grade through quartz-carbonate-albite-chlorite metasomatic schists to initial rocks, mainly of epidote-plagioclase-hornblende composition, often partly replaced by chlorite and biotite.
Hunter–Bowen deformation in South Percy Island, northeastern Australia
Published in Australian Journal of Earth Sciences, 2018
D. Hoy, G. Rosenbaum, N. Mortimer, U. Shaanan
The rocks hosting the shear zone include metamorphosed basalt, siltstone, sandstone, chert and a range of mafic and felsic intrusions. Metamorphic minerals in the mafic igneous rocks include chlorite + actinolite/tremolite + clinozoisite/epidote + albite/oligoclase + pumpellyite, and are typical of a greenschist-facies assemblage (Figure 3b). Felsic dykes also contain a typical greenschist-facies assemblage, comprising actinolite + chlorite + albite ± white mica (Figure 3d), in places with additional late syn- to post-kinematic growth of albite porphyroblasts. Epidote–clinozoisite occurs in many rocks both as syn-kinematic veins and by saussuritisation alteration of plagioclase, indicating that the circulation of Ca-rich fluids accompanied deformation and metamorphism. The rocks commonly contain a weak to strong syn-kinematic metamorphic fabric defined by chlorite + white mica + epidote ± actinolite, linking M1 greenschist-facies metamorphism with the major episode of deformation D1.