Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Cesarferreiraite, Fe (super 2+) Fe (sub 2) (super 3+) (AsO (sub 4) ) (sub 2) (OH) (sub 2) .8H (sub 2) O, from Eduardo Mine, Conselheiro Pena, Minas Gerais, Brazil; second arsenate in the laueite mineral group

Ricardo Scholz, Nikita V. Chukanov, Luiz A. D. Menezes Filho, Daniel Atencio, Leonardo Lagoeiro, Fernanda M. Belotti, Mario L. S. C. Chaves, Antonio W. Romano, Paulo R. Brandao, Dmitriy I. Belakovskiy and Igor V. Pekov
Cesarferreiraite, Fe (super 2+) Fe (sub 2) (super 3+) (AsO (sub 4) ) (sub 2) (OH) (sub 2) .8H (sub 2) O, from Eduardo Mine, Conselheiro Pena, Minas Gerais, Brazil; second arsenate in the laueite mineral group
American Mineralogist (April 2014) 99 (4): 607-611

Abstract

Cesarferreiraite, Fe (super 2+) Fe (sub 2) (super 3+) (AsO (sub 4) ) (sub 2) (OH) (sub 2) .8H (sub 2) O, is a new laueite-group mineral (IMA 2012-099) of triclinic symmetry, from Eduardo pegmatite mine, Conselheiro Pena municipality, Minas Gerais, Brazil. Intimately associated minerals are pharmacosiderite, scorodite, and earlier arsenopyrite, and probably cesarferreiraite replaces the latter. It occurs as fibrous-to-tabular aggregates up to 2 mm. Single crystals, up to 10 mu m long with a thickness of about 1-2 mu m, are elongated along [001] and flattened on (100). The fibers have almost rectangular cross-section apparently bound by the {100} and {010} pinacoid forms. Color and streak are pale to greenish yellow. Luster is vitreous; individual crystals are transparent and masses are translucent. Cleavage is distinct, presumably on {010} and {100}. Calculated density is 2.934 g/cm (super 3) . The mineral is biaxial (+), n (min) = 1.747(3), n (max) = 1.754(3) (589 nm). IR spectrum of cesarferreiraite is unique and can be used for the identification of the mineral. Chemical composition (n = 4, WDS, calculated for the condition Fe (super 2+) :Fe (super 3+) = 1:2, H (sub 2) O for the ideal structural formula, wt%) is: FeO 11.50, Fe (sub 2) O (sub 3) 25.56, CaO 15.41, As (sub 2) O (sub 5) 33.51, H (sub 2) O 26.01, total 100.12. The empirical formula (based on 18 O apfu) is Fe (super 2+) (sub 0.98) Fe (super 3+) (sub 1.96) [(AsO (sub 4) ) (sub 1.79) (PO (sub 4) ) (sub 0.31) ](OH) (sub 1. 52) .8.08H (sub 2) O. The strongest eight X-ray powder-diffraction lines [d in Aa(I)(hkl)] are: 9.85(95)(010), 6.35(100)(001), 3.671(29)(121), 3.158(32)(130), 2.960(39)(022), 2.884(35)(131), 2.680(29)(211), and 2.540(23)(210). Unit-cell parameters refined from powder data indexed by analogy with related laueite-group minerals (space group: P1) are: a = 5.383(2), b = 10.363(3), c = 6.878(2) Aa, alpha = 96.42(4), beta = 109.19(3), gamma = 102.30(2) degrees , V = 347.1(2) Aa (super 3) , and Z = 1. Gladstone-Dale compatibility is -0.020 (excellent). Cesarferreiraite is the arsenate analog of ferrolaueite.


ISSN: 0003-004X
EISSN: 1945-3027
Coden: AMMIAY
Serial Title: American Mineralogist
Serial Volume: 99
Serial Issue: 4
Title: Cesarferreiraite, Fe (super 2+) Fe (sub 2) (super 3+) (AsO (sub 4) ) (sub 2) (OH) (sub 2) .8H (sub 2) O, from Eduardo Mine, Conselheiro Pena, Minas Gerais, Brazil; second arsenate in the laueite mineral group
Affiliation: Universidade Federal de Ouro Preto, Departamento de Geologia, Ouro Preto, Brazil
Pages: 607-611
Published: 201404
Text Language: English
Publisher: Mineralogical Society of America, Washington, DC, United States
References: 11
Accession Number: 2014-030296
Categories: Mineralogy of non-silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 4 tables, sketch map
S19°10'00" - S19°10'00", W41°30'00" - W41°30'00"
Secondary Affiliation: Russian Academy of Sciences, Institute of Problems of Chemical Physics, RUS, Russian FederationUniversidade Federal de Minas Gerais, BRA, BrazilUniversidade de Sao Paulo, BRA, BrazilUniversidade Federal de Itajuba, BRA, BrazilRussian Academy of Sciences, Fersman Mineralogical Museum, RUS, Russian FederationMoscow State University, RUS, Russian Federation
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Mineralogical Society of America. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201419
Close Modal

or Create an Account

Close Modal
Close Modal