riebeckite


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Related to riebeckite: crocidolite

rie·beck·ite

 (rē′bə-kīt)
n.
A dark blue or greenish amphibole mineral, Na2Fe5Si8O22(OH)2, whose fibrous form is known as crocidolite asbestos.

[After Emil Riebeck (1853-1885), German explorer and mineralogist who in 1881 on an expedition to Socotra collected samples in which the mineral was later identified.]

riebeckite

(ˈriːbəˌkaɪt)
n
a mineral which is rich in sodium and is often translucent
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References in periodicals archive ?
According to Title 34 Labor and Workmens Compensation, Chapter 5A-34 (C.34:5A-34 Definitions)), asbestos is defined as asbestiform varieties of actinolite, amosite (cummuningtonitegrunerite), anthophyllite, chrysotile (serpentine), crocidolite (riebeckite) and tremolite.
At Sado field, hornblende in form of riebeckite occurs as minor phase and the source is the host lithology (metagabbro) [25].
[section] 61.141, states: "Asbestos means the asbestiform varieties of serpentinite (chrysotile), riebeckite (crocidolite), cummingtonite-grunerite, anthophyllite, and actinolite-tremolite." Other federal agencies have adopted similar definitions of asbestos that include the same six forms of asbestos, including 29 C.F.R.
The principal rock of the Warsak igneous complex is a medium-grained, gneissic alkaline granite (Kempe, 1973) composed of microcline with minor albite, quartz, aegirine, riebeckite and astrophyllite.
If it replaces a mineral called riebeckite, it forms a semiprecious gemstone called tiger's eye.
For regulatory purposes they are defined as the asbestiform varieties of chrysotile (serpentine), crocidolite (riebeckite), Amosite (cummingtonite-grunerite), anthophyllite, tremolite and actinolite.
The amphibole is greenish to brownish to blue, and in some rocks looks like typical riebeckite. The clinopyroxene is greenish pleochroic, and may range from aegirine augite to aegirine.
Numerous experimental animal studies have demonstrated the carcinogenicity of fibers of the six commercially used asbestos minerals [the serpentine chrysotile and the amphiboles cumming-tonite-grunerite asbestos (amosite), tremolite asbestos, riebeckite asbestos (crocidolite), actinolite asbestos, and anthophyliite asbestos in multiple species (rats, hamsters, mice) by exposure via inhalation, intrapleural injection, implantation, and ingestion (reviewed by Kamp 2009; Lippmann 1990).
Arfvedsonite prevails while riebeckite (Fediuk, 2005), for which most manuals on systematic mineralogy claim Socotra for the locus typicus, is substantially less frequent and mostly restricted to narrow rims of zoned amphibole columns only.
Associated minerals are: riebeckite, analcime, sodalite and steenstrupine-(Ce).
The minerals include K-feldspar (microcline), quartz, plagioclase, biotite, aegirine-augite, hornblende, riebeckite, titanite, epidote, apatite, zircon and magnetite.
These include microscopic black crystals of ilvaite associated with prehnite or datolite, and fibrous blue coatings of riebeckite on basalt surfaces (Bradley Platkin, personal communication).