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GEOREF RECORD

Recommended nomenclature of epidote-group minerals

Thomas Armbruster, Paola Bonazzi, Masahide Akasaka, Vladimir Bermanec, Christian Chopin, Reto Giere, Soraya Heuss-Assbichler, Axel Liebscher, Silvio Menchetti, Yuanming Pan and Marco Pasero
Recommended nomenclature of epidote-group minerals
European Journal of Mineralogy (October 2006) 18 (5): 551-567

Abstract

The minerals of the epidote group have monoclinic symmetry and topology consistent with space group P2 (sub 1) /m and the general formula A (sub 2) M (sub 3) [T (sub 2) O (sub 7) ][TO (sub 4) ](O,F)(OH,O). Zoisite is an orthorhombic polymorph of clinozoisite Ca (sub 2) Al (sub 3) [Si (sub 2) O (sub 7) ][SiO (sub 4) ]O(OH) and is thus not considered here as a member of the epidote group. The epidote group minerals are classified into three subgroups. 1) Members of the clinozosite subgroup derived from clinozoisite by homovalent substitutions only; the key cation and anion sites are A1 = M2, A2 = M (super 2+) , M1 = M (super 3+) , M2 =M (super 3+) , M3 = M (super 3+) , O4 = O (super 2-) , O10 = (OH) (super -) , i.e. the dominant valence as listed above must be maintained. 2) Members of the allanite subgroup are REE-rich minerals typified by the eponymous mineral "allanite"; this subgoup may be derived from clinozoisite by homovalent substitutions and one coupled hetereovalent substitution of the type (super A) (super 2) (REE) (super 3+) + (super M) (super 3) M (super 2+) --> (super A) (super 2) Ca (super 2+) + (super M) (super 3) M (super 3+) ; thus the valencies of the key sites are A1 = M (super 2+) , A2 = M (super 3+) , M1 = M (super 3+) , M2 = M (super 3+) , M3 = M (super 2+) , O4 = O (super 2-) , O 10 = (OH) (super -) . 3) Members of the dollaseite subgroup are REE-rich minerals typified by the mineral dollaseite; this subgroup may be derived from clinozosite by homovalent substitutions and two coupled heterovalent substitutions of the type (super A) (super 2) (REE) (super 3+) + (super M) (super 3) M (super 2+) --> (super A) (super 2) Ca (super 2+) + (super M) (super 3) M (super 3+) and (super M) (super 1) M (super 2+ ) + (super O4) F (super -) --> (super M) (super 1) M (super 3+ ) + (super O4) O (super 2-) . The use of the prefixes ferri, mangani, chromo and vanado are used to indicate dominant Fe (super 3+) , Mn (super 3+) , Cr (super 3+ ) or V (super 3+) on M1. This nomenclature requires the renaming of niigataite as clinozoisite-(Sr), hancockite as epidote-(Pb), tweddillite as manganipiemontite-(Sr), strontiopiemontite as piemontite-(Sr) and androsite-(La) as manganiandrosite-(La). Formal guidelines and examples are provided in order to determine a "working name" from EPMA data.


ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 18
Serial Issue: 5
Title: Recommended nomenclature of epidote-group minerals
Affiliation: Universitaet Bern, Laboratorium fuer Chemische und Mineralogische Kristallographie, Bern, Switzerland
Pages: 551-567
Published: 200610
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 88
Accession Number: 2007-008232
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Annotation: Includes appendices
Illustration Description: illus. incl. 8 tables
Secondary Affiliation: Universita di Firenze, ITA, ItalyShimane University, JPN, JapanUniversity of Zagreb, HRV, CroatiaEcole Normale Superieure, FRA, FranceAlbert-Ludwigs-Universitaet, DEU, Federal Republic of GermanyLudwig-Maximilians-Universitaet, DEU, Federal Republic of GermanyGeoForschungsZentrum Potsdam, DEU, Federal Republic of GermanyUniversity of Saskatchewan, CAN, CanadaUniversita di Pisa, ITA, Italy
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 200704
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