Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-27T05:26:26.907Z Has data issue: false hasContentIssue false

Cerchiaraite-(Fe) and cerchiaraite-(Al), two new barium cyclosilicate chlorides from Italy and California, USA

Published online by Cambridge University Press:  05 July 2018

A. R. Kampf*
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA
A. C. Roberts
Affiliation:
Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada
K. E. Venance
Affiliation:
Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada
C. Carbone
Affiliation:
DISTAV, Universita` degli Studi di Genova, Corso Europa 26 - 16132 Genova, Italy
D. Belmonte
Affiliation:
DISTAV, Universita` degli Studi di Genova, Corso Europa 26 - 16132 Genova, Italy
G. E. Dunning
Affiliation:
773 Durshire Way, Sunnyvale, California 94087, USA
R. E. Walstrom
Affiliation:
P.O. Box 1978, Silver City, New Mexico 88062, USA
*
* E-mail: akampf@nhm.org

Abstract

The ideal formula for members of the cerchiaraite group is Ba4M4(Si4O12)O2(OH)4Cl2[Si2O3(OH)4], where M represents Mn3+, Fe3+ or Al in the octahedral site. A suffix-based naming scheme is used in which the original cerchiaraite is renamed cerchiaraite-(Mn) and two new minerals are named cerchiaraite-(Fe) and cerchiaraite-(Al). The type localities for cerchiaraite-(Fe) are the Cerchiara mine, Liguria, Italy and the Esquire No. 7 and No. 8 claims, Big Creek, Fresno County, California, USA. The type localities for cerchiaraite-(Al) are the Esquire No. 1 claim, Rush Creek, Fresno County, California, USA and the Esquire No. 7 and No. 8 claims noted above. At the Cerchiara mine, cerchiaraite-(Fe) occurs in small fractures and veinlets in a Jurassic ophiolitic sequence. It is of secondary hydrothermal origin and occurs as tan to brown thin prisms and matted fibres. Cerchiaraite(Fe) and cerchiaraite-(Al) from the Esquire No. 1, No. 7 and No. 8 claims occur in parallel-bedded quartz-sanbornite vein assemblages which formed as a result of fluid interaction along the margin of the vein. At the Esquire No. 1, No. 7 and No. 8 claims, both cerchiaraite-(Fe) and cerchiaraite-(Al) occur as subparallel aggregates of blue to bluish green irregular prisms. Both minerals are transparent with a vitreous lustre, Mohs hardness ~4½ , brittle tenacity, irregular fracture and no cleavage. The calculated density of cerchiaraite-(Fe) is 3.710 g cm-3; the measured density of cerchiaraite-(Al) is 3.69(3) g cm-3and the calculated density is 3.643 g cm-3. Cerchiaraite-(Fe) is uniaxial (+), with ω = 1.741(2) and ε = 1.768(2); it is weakly pleochroic and O is colourless and E is yellow. Cerchiaraite-(Al) is uniaxial (-), with ω = 1.695(2) and e = 1.677(2); it is strongly pleochroic and O is colourless and E is blue. Electron-microprobe analyses yielded empirical formulae ranging from (Ba3.82Na0.02Ca0.04)Σ3.88(Fe3+3.42Ti4+0.27Al3+0.25Mn3+0.04Mg0.02)Σ4.00Si5.62O15.47(OH)9.31Cl2.22 (Cerchiara mine) to Ba4.00(Al3+2.40Fe3+1.12Mg0.15Fe2+0.12Mn2+0.06)Σ3.85Si5.78O15.34(OH)8.75Cl2.91 (Esquire No. 1 claim). Cerchiaraite is tetragonal with Z = 2 and crystallizes in space group I4/mmm. The cell parameters for cerchiaraite-(Fe) are a = 14.3554(12), c = 6.0065(5) Å and V = 1237.80(5) Å3; those for cerchiaraite(Al) are a = 14.317(4), c = 6.0037(18) Å and V = 1230.6(6) Å3. In the cerchiaraite-(Fe) structure, SiO4 tetrahedra share corners forming a four-membered Si4O12 ring. The ring is corner-linked to an edgesharing chain of Fe3+ O6 octahedra running parallel to c. A Cl site alternates along c with the Si4 O12 ring. A large channel in the framework contains Ba atoms around its periphery and statistically distributed Si2 O7 silicate dimers and Cl atoms. The strong blue pleochroic colour is attributed to Fe2+ - Fe3+intervalence charge transfer along the octahedral chain.

Type
Letter
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alfors, J.T., Stinson, M.C., Matthews, R.A. and Pabst, A. (1965) Seven new barium minerals from eastern Fresno County, California. American Mineralogist, 50, 314340.Google Scholar
Alfors, J.T. and Pabst, A. (1984) Titanian taramellites in western North America. American Mineralogist, 69, 358373.Google Scholar
Armstrong, J.T. (1988) Quantitative analysis of silicates and oxide minerals: comparison of Monte-Carlo, ZAF and Phi-Rho-Z procedures. Pp. 239–246. in: Microbeam Analysis (D.E. Newbury, editor). San Francisco Press, San Francisco, USA.Google Scholar
Basciano, L.C., Groat, L.A., Roberts, A.C., Gault, R.A., Dunning, G.E. and Walstrom, R.E. (2001a) Bigcreekite, a new mineral from eastern Fresno County, California. The Canadian Mineralogist, 39, 761768.CrossRefGoogle Scholar
Basciano, L.C., Groat, L.A., Roberts, A.C., Grice, J.D., Dunning, G.E., Foord, E.E., Kjarsgaard, I. and Walstrom, R.E. (2001b) Kampfite, a new barium silicate mineral from Fresno County, California. The Canadian Mineralogist, 39, 10531058.CrossRefGoogle Scholar
Basso, R., Lucchetti, G., Zefiro, L. and Palenzona, A. (2000) Cerchiaraite, a new natural Ba-Mn-mixedanion silicate chloride from the Cerchiara mine, northern Apennines, Italy. Neues Jahrbuch für Mineralogie, Monatschefte, 2000, 373384.Google Scholar
Brese, N.E. and O’Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192197.CrossRefGoogle Scholar
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244247.CrossRefGoogle Scholar
Burla, M.C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G.L., De Caro, L., Giacovazzo, C., Polidori, G. and Spagna, R. (2005) SIR2004: an improved tool for crystal structure determination and refinement. Journal of Applied Crystallography, 38, 381388.CrossRefGoogle Scholar
Cabella, R., Lucchetti, G., Palenzona, A., Quartieri, S. and Vezzalini, G. (1993) First occurrence of a Badominant brewsterite: structural features. European Journal of Mineralogy, 5, 353360.CrossRefGoogle Scholar
Dunning, G.E. and Cooper, J.F. Jr (1999) Barium silicate minerals from Trumbull Peak, Mariposa County, California. Mineralogical Record, 30, 411417.Google Scholar
Grice, J.D., Nickel, E.H. and Gault, R.A. (1991) Ashburtonite, a new bicarbonate-silicate mineral from Ashburton Downs, Western Australia: description and structure determination. American Mineralogist, 76, 17011707.Google Scholar
Kampf, A.R., Rossman, G.R., Steele, I.M., Pluth, J.J., Dunning, G.E. and Walstrom, R.E. (2010) Devitoite, a new heterophyllosilicate with astrophyllite-like layers from eastern Fresno County, California. The Canadian Mineralogist, 48, 2940.CrossRefGoogle Scholar
Kampf, A.R., Roberts, A.C., Venance, K.E., Dunning, G.E. and Walstrom, R.E. (2011) Ferroericssonite, the Fe2+-analogue of ericssonite from eastern Fresno County, California, U.S.A. The Canadian Mineralogist, 49, 587594.CrossRefGoogle Scholar
Kampf, A.R., Pluth, J.J., Chen, Y.-S., Roberts, A.C. and Housley, R.M. (2013) Bobmeyerite, a new mineral from Tiger, Arizona,, USA, structurally related to cerchiaraite and ashburtonite. Mineralogical Magazine, 77, 8191.CrossRefGoogle Scholar
Lucchetti, G., Cortesogno, L. and Palenzona, A. (1988) Low-temperature metamorphic mineral assemblages in Mn-Fe ores from Cerchiara mine (northern Apennine, Italy). Neues Jahrbuch für Mineralogie Monatshefte, 1988, 367383.Google Scholar
Mandarino, J.A. (1981) The Gladstone–Dale relationship: part IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441450.Google Scholar
Mills, S.J., Hatert, F., Nickel, E.H. and Ferraris, G. (2009) The standardisation of mineral group hierarchies: application to recent nomenclature proposals. European Journal of Mineralogy, 21, 10731080.CrossRefGoogle Scholar
Montgomery, J.H., Thompson, R.M. and Meagher, E.P. (1972) Pellyite: a new barium silicate mineral from the Yukon Territory. The Canadian Mineralogist, 11, 444447.Google Scholar
Newberry, N.G., Essene, E.J. and Peacor, D.R. (1981) Alforsite, a new member of the apatite group: the barium analogue of chlorapatite. American Mineralogist, 66, 10501053.Google Scholar
Roberts, A.C., Grice, J.D., Dunning, G.E. and Venance, K.E. (2001) Fencooperite, Ba6Fe3+ 3 Si8O23 (CO3)2Cl3·H2O, a new mineral species from Trumbull Peak, Mariposa County, California. The Canadian Mineralogist, 39, 10591064.CrossRefGoogle Scholar
Rogers, A.F. (1932) Sanbornite, a new barium silicate mineral from Mariposa County, California. American Mineralogist, 17, 161172.Google Scholar
Sheldrick, G.M. (2008) SHELXL97 – Program for the Refinement of Crystal Structures. University of Göttigen, Göttigen, Germany.Google Scholar
Stormer, J.C., Pierson, M.L. and Tacker, R.C. (1993) Variation of F and Cl X-ray intensity due to anisotropic diffusion in apatite during electron microprobe analysis. American Mineralogist, 78, 641648.Google Scholar
Walstrom, R.E. and Dunning, G.E. (2003) The Baumann prospect, Chickencoop Canyon, Tulare County, California. Mineralogical Record, 34, 159166.Google Scholar
Walstrom, R.E. and Leising, J.F. (2005) Barium minerals of the sanbornite deposits, Fresno County, California. Axis, 1, 118.Google Scholar
Supplementary material: File

Kampf et al. supplementary material

Structure factors

Download Kampf et al. supplementary material(File)
File 32.3 KB