Tirodite
Classification:
Tirodite is an amphibole and related to cummingtonite. In its fibrous form, it is also called asbestos ; compare to cummingtonite, asbestos .
Synonyms/Trade Names:
Amphibole.
Chemistry/Composition:
(Mg,Fe)7(OH/Si4O11) . It normally contains <40% Fe replacing Mg and contaminations of F replacing OH. It contains <8% MnO .
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.
Crystallographic Constants:
9.799 17.990 5.289 90.000 103.890 90.000.
Crystal Group:
Monoclinic.
Color:
colorless.
Optical Properties:
nx=1.644-1.685 ny=1.657-1.709 nz=1.614-1.728.
Pleochroism:
Yellow to brown.
Powder Diagram:
8.42 3.13 3.27 2.81 (23-603).
Natural Sources:
World-wide.
Medical Importance:
Key Hazards:
Possibly fibrogenic, possibly mutagenic.
Involved Organs:
Probably lung.
Exposure/Epidemiology:
Exposure or technical use is not known.
Thresholds:
In Germany, MAK 6 mg/m3.
Etiology/Pathophysiology:
Detailed data are not known.
Lung Diseases:
Associated specific diseases are not known; however, the mineral is listed by the ISO, i.e., possibly fibrogenic and mutagenic forms exist.
Clinical Presentation:
Associated specific symptoms are not known.
Radiology:
Associated specific findings are not known.
Lung Function:
Usually normal findings.
Bronchoalveolar Lavage:
Usually normal findings.
Pathology:
Gross:
The lungs are of normal color and consistency.
Histology:
The alveoli can contain an increased number of macrophages, and collections of brown dust particles may be seen in the lymphatic tissue.
Prognosis:
Usually good and without serious sequelae.
Additional Diseases:
None.
References:
search Pubmed for Tirodite