Anthophyllite
Classification:
Anthophyllite is an amphibole and related to the amphibole cummingtonite. Both are called asbestos if they have a fibrous form; for details, see under the heading amphibole .
Cas:
17068-78-9, 77536-67-5
Synonyms/Trade Names:
Amosite, Anthogrammit, Antholith, Asbestos, Azbolen Asbestos, Monasite, Strelit.
Chemistry/Composition:
(Mg,Fe)7(OH/Si4O11)2 . It contains <40% Fe2+ and only contaminations of F (instead of OH) .
Structure:
The silicon and aluminum atoms containing oxygen tetrahedra are linked and form chains. Two of these chains are bonded, respectively, and form a double chain, which is built by rings of six-membered tetrahedra. Two tetrahedra belong to the two neighboring rings, respectively, and only two of them to the ring itself. The chains can be described by the chemical formula (Si4O11)n. The separated chains are bonded by cations and partially by hydroxyl ions. The surface charge is negative.
Crystallographic Constants:
18.500 17.900 (18.08) 5.290 90.000 90.000 90.000.
Crystal Group:
Orthorhombic.
Color:
Brown, yellow-brown, or green-brown.
Optical Properties:
nx=1.589-1.647 ny=1.616-1.651 nz=1.623-1.664.
Pleochroism:
colorless.
Powder Diagram:
3.05 3.24 8.26 2.84 (9-455).
Natural Sources:
Mined in Australia (Hamersley), Finland (Paakila, Rikkavesi, Usinmski), Germany (Bodenmais), Norway (Kongsberg), Russia (Sverdlovsk), and the USA (Sall Mountains/ Georgia, North Carolina).
Varieties:
• Bedenite
Specification:
It is an amphibole and related to anthophyllite. It is also called asbestos .
Chemistry/Composition:
Ca2(Mg,Fe3+,Al)5(OH/(Si,Al)4O11)2 .
Structure:
Identical to anthophyllite.
Crystallographic Constants:
18.500 17.900 5.290 90.000 90.000 90.000.
Crystal Group:
Orthorhombic.
Color:
Brown, yellow-brown or green-brown.
Optical Properties:
nx=1.589-1.647 ny=1.616-1.651 nz=1.623-1.664.
Pleochroism:
colorless.
Powder Diagram:
3.05 3.24 8.26 2.84 (9-455).
Natural Sources:
Finland, France, Germany (Black Forest), and Norway.
• Ferrogedrite
Specification:
Amphibole mineral, which is a Fe-rich variety of gedrite.
Chemistry/Composition:
Fe2+5Al2(OH/AlSi3O11)2 .
Structure:
Identical to anthophyllite.
Crystallographic Constants:
18.500 17.900 (18.08) 5.290 90.000 90.000 90.000.
Crystal Group:
Orthorhombic.
Color:
Brown, yellow-brown, or green-brown.
Optical Properties:
nx=1.589-1.647 ny=1.616-1.651 nz=1.623-1.664.
Pleochroism:
colorless.
Powder Diagram:
3.05 3.24 8.26 2.84 (9-455).
Natural Sources:
Japan.
• Gedrite
Specification:
It is an amphibole mineral, which normally crystallizes in a fibrous form.
Chemistry/Composition:
(Mg,Fe)6-5Al1-2(OH/(Al,Si)Si3O11)2 .
Structure:
Identical to anthophyllite.
Crystallographic Constants:
18.6 18.0 5.3 90.000 90.000 90.000.
Crystal Group:
Orthorhombic.
Color:
Yellow-gray to brown.
Optical Properties:
nx=1.642-1.674 ny=1.651-1.681 nz=1.658-1.691.
Pleochroism:
Yellow to brown.
Powder Diagram:
3.06 8.27 3.23 9.97.
Natural Sources:
Finland, France, Germany (Black Forest), and Norway.
Medical Importance:
Key Hazards:
Fibrogenic, carcinogenic.
Involved Organs:
Lung, peritoneum, skin, kidneys.
Exposure/Epidemiology:
The amphibole minerals are of great technical interest. Their fibrous form is related to their specific physical properties such as heat resistance, electrical insulation, etc. Important sources of exposure are shipyards, manufacture of fire-resistant textiles, sheets, automobile brakes, filters for various fluids, etc. For details, see under the heading asbestos .
Thresholds:
See under the heading asbestos .
Etiology/Pathophysiology:
The inhaled fibers activate complement-derived chemotactic activity on alveolar surfaces, pneumocytes, macrophages, and mesothelial cells. Immunologic compartments such as interleukins and tumor necrosis factor are probably involved. For details, see under the heading asbestos .
Lung Diseases:
All amphibole s can crystallize in fibrous varieties:, and can induce interstitial lung fibrosis, pleural diseases such as fibrosis, pleural plaques, benign and malignant tumors of the lung, pleura, peritoneum, gastrointestinal tract, lymphatic system, and kidneys. For details, see under the heading asbestos .
Clinical Presentation:
Chronic cough and shortness of breath during physical exercise are usually the first symptoms; chest pain is often associated with pleural tumors.
Radiology:
Chest radiographs are often normal in patients with early changes. Others may display diffuse interstitial densities, pleural thickening, or effusions.
Lung Function:
Progressive restrictive changes or severe obstructive changes are seen.
Bronchoalveolar Lavage:
The inhaled mineral fibers can be analyzed and quantified in the lavage fluid. Increased levels of complement C5 or altered ratio of the T4/T8 lymphocytes correspond with the activity of the fibrotic lesions.
Pathology:
Gross:
The lungs may display an increased consistency, a thickened and fibrotic pleura, honeycombing, or circumscribed white-yellowish tumor masses. For details, see under the heading asbestos .
Histology:
The fibers are birefringent and often coated with iron-protein mucopolysaccharide substances (asbestos bodies). They are usually deposited in the distant airways and can be ingested by macrophages. Diffuse interstitial fibrosis associated with scattered mononuclear inflammatory infiltrates and acellular collagenous fibers in the pleura are common findings. Benign and malignant tumors of various cell types (most frequently common lung carcinoma and mesothelioma) can develop. For details, see under the heading asbestos.
Prognosis:
Usually poor due to serious sequelae.
Additional Diseases:
See under the heading asbestos .
References:
search Pubmed for Anthophyllite
Doll R: The quantitative significance of asbestos fibres in ambient air. Experimentia Suppl 51 (1987) 213-219
McDonald JC, Armstrong B, case B, Doell D, McCaughey WT, McDonald AD: Mesothelioma and asbestos fibre type. Cancer 8 (1989) 1544-1547
Gerde P, Scholander P: Adsorption of polycyclic aromatic hydrocarbons on to asbestos and man-made mineral fibres. IARC Sci Publ 90 (1989) 140-148
Lewis RJ: Carcinogenically active chemicals. Van Nostrand Reinhold, New York (1991)
Merchant JA: Human epidemiology: a review of fiber type and characteristics in the development of malignant and nonmalignant disease. Environ Health Perspect 88 (1990) 287-293
Tuomi T, Segerberg-Konttinen M, Tammilehto L, Tossavainen A: Mineral fibre concentration in lung tissue of mesothelioma patients in Finland. Am J Ind Med 3 (1989) 247-254