Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Mineralogical Magazine Email Content Delivery
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Mineralogical Magazine; February 2004; v. 68; no. 1; p. 135-146; DOI: 10.1180/0026461046810176
© 2004 Mineralogical Society of Great Britain and Ireland
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (4)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lennie, A. R.
Right arrow Articles by Thompson, S. P.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

The structure and thermal expansion behaviour of ikaite, CaCO3.6H2O, from T = 114 to T = 293 K

A. R. Lennie*, C. C. Tang and S. P. Thompson

Daresbury Laboratory, Warrington, Cheshire WA4 4AD, UK

* E-mail: a.lennie{at}dl.ac.uk

The hydrous calcium carbonate mineral ikaite (CaCO3.6H2O) forms in nature at low temperature in carbonate- and Ca-rich waters. Ikaite crystallizes in the spacegroup C2/c, and consists of CaCO3.6H2O units with Ca ions coordinated by eight oxygens, six from H2O and two from the carbonate group. Hydrogen bonding links CaCO3.6H2O moieties to form the crystal structure.

We have used synchrotron X-ray powder diffraction at T = 243 K to refine the monoclinic structure of ikaite, and have measured unit-cell parameters of ikaite between T = 114 K and T = 293 K. Anisotropic thermal expansion in ikaite is evident, with the smallest relative increase occurring along the b direction parallel to 2-fold axes. The contribution of hydrogen bonding to thermal expansion is assessed by comparison of our data with previously published data for deuterated ikaite, ice and gypsum. Ikaite exhibits a coefficient of volume expansion intermediate between that of ice (Ih) and of deuterated gypsum (CaSO4.2D2O) between T = 114 K and T = 293 K.

KEYWORDS: ikaite, carbonate, crystal structure, thermal expansion, hydrogen bonding




This article has been cited by other articles:


Home page
 American MineralogistHome page
I. P. Swainson
The structure of monohydrocalcite and the phase composition of the beachrock deposits of Lake Butler and Lake Fellmongery, South Australia
American Mineralogist, July 1, 2008; 93(7): 1014 - 1018.
[Abstract] [Full Text] [PDF]

Home page
 Journal of Sedimentary ResearchHome page
B. W. Selleck, P. F. Carr, and B. G. Jones
A Review and Synthesis of Glendonites (Pseudomorphs after Ikaite) with New Data: Assessing Applicability as Recorders of Ancient Coldwater Conditions
Journal of Sedimentary Research, November 1, 2007; 77(11): 980 - 991.
[Abstract] [Full Text] [PDF]

Home page
 GeologyHome page
R.E.M. Rickaby, S. Shaw, G. Bennitt, H. Kennedy, M. Zabel, and A. Lennie
Potential of ikaite to record the evolution of oceanic {delta}18O
Geology, June 1, 2006; 34(6): 497 - 500.
[Abstract] [Full Text] [PDF]

Home page
 Mineral MagHome page
A. R. Lennie
Ikaite (CaCO3{middle dot}6H2O) compressibility at high water pressure: a synchrotron X-ray diffraction study
Mineralogical Magazine, June 1, 2005; 69(3): 325 - 335.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Mineralogical Society of Great Britain and Ireland