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Ferri-clinoholmquistite, Li 2 (Fe (super 2+) ,Mg) 3 Fe (super 3+) 2 Si 8 O 22 (OH) 2 , a new B Li clinoamphibole from the Pedriza Massif, Sierra de Guadarrama, Spanish Central System

1998; Mineralogical Society of America; Volume: 83; Issue: 1-2 Linguagem: Inglês

10.2138/am-1998-1-217

1945-3027

José María Caballero, Ángeles Monge, Á. La Iglesia, Fernando Tornos,

Crystal Structures and Properties

Other| February 01, 1998 Ferri-clinoholmquistite, Li 2 (Fe (super 2+) ,Mg) 3 Fe (super 3+) 2 Si 8 O 22 (OH) 2 , a new B Li clinoamphibole from the Pedriza Massif, Sierra de Guadarrama, Spanish Central System Jose M. Caballero; Jose M. Caballero Universidad Complutense de Madrid, Departmento de Petrologia y Geoquimica, Madrid, Spain Search for other works by this author on: GSW Google Scholar Angeles Monge; Angeles Monge CSIC Instituto de Ciencia de los Materials, Madrid, Spain Search for other works by this author on: GSW Google Scholar Angel La Iglesia; Angel La Iglesia CSIC Instituto de Geologia Economica, Madrid, Spain Search for other works by this author on: GSW Google Scholar Fernando Tornos Fernando Tornos Instituto Tecnologico Geominero de Espana, Madrid, Spain Search for other works by this author on: GSW Google Scholar American Mineralogist (1998) 83 (1-2): 167–171. https://doi.org/10.2138/am-1998-1-217 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Jose M. Caballero, Angeles Monge, Angel La Iglesia, Fernando Tornos; Ferri-clinoholmquistite, Li 2 (Fe (super 2+) ,Mg) 3 Fe (super 3+) 2 Si 8 O 22 (OH) 2 , a new B Li clinoamphibole from the Pedriza Massif, Sierra de Guadarrama, Spanish Central System. American Mineralogist 1998;; 83 (1-2): 167–171. doi: https://doi.org/10.2138/am-1998-1-217 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Ferri-clinoholmquistite is a new amphibole species from episyenites in the East Pedriza Massif (Central System, Spain), where it is associated to albite, augite-aegirine, titanite, andradite, magnetite, and apatite. It is black, vitreous, translucent, non-fluorescent, and brittle. It shows gray streak, H(Mohs) = 6, splintery fracture, perfect {110} cleavage, (001) parting, D meas = 3.19, and D cal = 3.25. Crystals are prismatic, elongated on [001]. In plane-polarized light, it is strongly pleochroic: X = yellow green, Y = indigo blue, Z = green blue, with absorption X<Y< or =Z; Z = b, Y - c = 10(2) degrees , X - a approximately -2 degrees (in beta obtuse). Ferri-clinoholmquistite is biaxial positive, alpha = 1.699(2), beta = 1.703(2), gamma = 1.708(2), 2V Z (meas) = 72(7), 2V Z (calc) = 84(6), r<v. It is monoclinic, space group C2/m, a = 9.472(4), b = 17.844(6), c = 5.276(6) Aa, beta = 101.97(9) degrees , V = 872(1) Aa 3 , Z = 2. X-ray powder-diffraction pattern data were determined. Analysis by a combination of electron microprobe and flame photometry gives the following formula, calculated assuming OH+F = 2 and T sites fully occupied by Si: A (Na (sub 0.43) K (sub 0.03) ) B (Li (sub 1.66) Na (sub 0.30) Ca (sub 0.04) ) C (Fe (super 3+) (sub 1.54) Fe (super 2+) (sub 1.35) Mg (sub 1.21) Li (sub 0.49) Al (sub 0.20) Ti (super 4+) (sub 0.12) Mn (super 2+) (sub 0.07) Zn (sub 0.02) ) T (Si 8 )O 22 (OH (sub 1.58) F (sub 0.42) ). From crystallographic refinements the M4 site is split, implying ordering of Li and Na, and within the A cavity, Na occupies the Am position. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.