Alunite
Classification:
Alunite is a sulfate, and occasionally used as aluminum ore; for details, see under the heading aluminum.
Synonyms/Trade Names:
Alaun, Calafarit, Newtonit.
Chemistry/Composition:
MeI(MeIII I 3(SO4)2(OH)6) with Me =Na, K, Rb, III Ag, H3O, NH4, and Me = Al, Fe, Ga, In .
Structure:
Alunite has a sheet-Structure with layers of MeIII (SO ) (OH) (H 0) groups and layers of MeI(H2O).
Crystallographic Constants:
6.79 6.79 17.38 60.000 60.000 90.000.
Crystal Group:
Trigonal.
Color:
Normally colorless or white, grayish, reddish-brown, seldom reddish.
Optical Properties:
nO=1.572 nE=1.592.
Pleochroism:
colorless.
Powder Diagram:
2.99 2.89 2.29 1.93 (14-136)
1.90 1.75 3.01 2.29 ( 4-865).
Natural Sources:
Mined in Australia, Slov. Rep./Czec. Rep., France, Italy, Rumania, Spain, and the USA.
Medical Importance:
Key Hazards:
Not known.
Involved Organs:
Probably lung.
Exposure/Epidemiology:
Exposure can occur during mining and processing, and in agriculture.
Thresholds:
In Germany, MAK 6 mg/m3.
Etiology/Pathophysiology:
The inhaled fibers are probably inert and not hazardous.
Lung Diseases:
It has been assumed that alunite can induce interstitial Lung Diseases; this could, however, not be verified.
Clinical Presentation:
Associated symptoms are not known.
Radiology:
Chest radiographs are normal.
Lung Function:
No abnormal findings.
Bronchoalveolar Lavage:
No abnormal findings.
Pathology:
Gross:
No abnormal findings.
Histology:
The inhaled fibers are birefringent and deposited in the distant airways. They can be phagocytosed by macrophages and may be noted in the lymphatic tissue. The interstitial lung parenchyma is of normal appearance.
Prognosis:
Usually good and without serious sequelae.
Additional Diseases:
None.
References:
search Pubmed for Alunite
Preisinger A, Mereiter K, Aslanian S: Defekt-Alunite: Hydrothermalsynthese und Kristallstruktur. Europ J Min 3, 2 supp (1991) 216
Musk AW, Beck BD, Grewille HW, Brain JD, Bohannon DE: Pulmonary disease from exposure to an artificial aluminum silicate: further observations. Br J Ind Med 4 (1988) 246-250