Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Structural interpretation of a new twin in staurolite from Coray, Brittany, France

Massimo Nespolo and Yves Moelo
Structural interpretation of a new twin in staurolite from Coray, Brittany, France
European Journal of Mineralogy (March 2019) 31 (4): 785-790

Abstract

A new twin in staurolite has been recently reported from Coray (Brittany, France). From morphological measurements the twin plane has been identified as (202), which corresponds to twinning by reticular pseudomerohedry with index 3 and obliquity 0.97 degrees . On the basis of the high-degree of lattice restoration, significantly higher than that in the other well-known twins in staurolite (Greek cross and Saint Andrews cross), one would expect a high probability of occurrence for this twin. Its rarity can be explained on structural bases. The interface corresponding to the twin plane leads to a highly disrupted coordination, where only half of the tetrahedra are restored. This makes a contact twin highly unlikely. The reported twin is actually a penetration twin, in which the irregular composition surface may have compensated, to some extent, the unfavourable structural match.


ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 31
Serial Issue: 4
Title: Structural interpretation of a new twin in staurolite from Coray, Brittany, France
Affiliation: Universite de Lorraine, Cristallographie, Resonance Magnetique et Modelisations, Nancy, France
Pages: 785-790
Published: 20190330
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Germany
References: 26
Accession Number: 2019-032169
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table
N48°04'00" - N48°04'00", W03°49'60" - W03°49'60"
Secondary Affiliation: Universite de Nantes, FRA, France
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Abstract, copyright, Schweizerbart'sche Verlagsbuchhandlung. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201917
Close Modal

or Create an Account

Close Modal
Close Modal