Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Crystal chemistry of superfluorous phase B (Mg (sub 10) Si (sub 3) O (sub 14) F (sub 4) ); implications for the role of fluorine in the mantle

Robert M. Hazen, Hexiong Yang, Charles T. Prewitt and Tibor Gasparik
Crystal chemistry of superfluorous phase B (Mg (sub 10) Si (sub 3) O (sub 14) F (sub 4) ); implications for the role of fluorine in the mantle
American Mineralogist (June 1997) 82 (5-6): 647-650

Abstract

Single-crystal X-ray diffraction data have been obtained for crystals of the F analog of superhydrous phase B, Mg (sub 10) Si (sub 3) O (sub 14) F (sub 4) . Twinned crystals were synthesized using a splitsphere anvil apparatus (USSA-2000) at pressures between 17.8 and 22.3 GPa and temperatures between 1450 and 1600 degrees C. Orthorhombic (space group Pnnm) unit-cell parameters are a = 5.050(3), b = 13.969(2), and c = 8.640(3) Aa. The substitution of F for H results in minor crystal chemical changes. Notably, average Mg-F distances (1.95 Aa) are shorter than the corresponding average of Mg-OH distances (1.98 Aa). These differences are reflected in shortening of unit-cell axes a and c in superfluorous B by 0.6 and 0.8%, respectively, relative to superhydrous B, while the b axis is unchanged. The close similarities between superhydrous and superfluorous B phases suggest that F will usually substitute for OH- in mantle phases.


ISSN: 0003-004X
EISSN: 1945-3027
Coden: AMMIAY
Serial Title: American Mineralogist
Serial Volume: 82
Serial Issue: 5-6
Title: Crystal chemistry of superfluorous phase B (Mg (sub 10) Si (sub 3) O (sub 14) F (sub 4) ); implications for the role of fluorine in the mantle
Affiliation: Carnegie Institution of Washington, Geophysical Laboratory and Center for High Pressure Research, Washington, DC, United States
Pages: 647-650
Published: 199706
Text Language: English
Publisher: Mineralogical Society of America, Washington, DC, United States
References: 17
Accession Number: 1997-055759
Categories: Geophysics of minerals and rocks
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: 3 tables
Secondary Affiliation: State University of New York at Stony Brook, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute.
Update Code: 199718
Close Modal

or Create an Account

Close Modal
Close Modal