Non-aqueous formation of the calcium carbonate polymorph vaterite: astrophysical implications

DOI: 10.1051/0004-6361/201321138

Authors: S. J. Day (University of Keele) , S. P. Thompson (Diamond Light Source) , J. E. Parker (Diamond Light Source) , A. Evans (Keele University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Astronomy & Astrophysics

State: Published (Approved)
Published: March 2013
Diamond Proposal Number(s): 6515

Abstract: Aims. We study the formation of calcium carbonate, through the solid-gas interaction of amorphous Ca-silicate with gaseous CO2, at elevated pressures, and link this to the possible presence of calcium carbonate in a number of circumstellar and planetary environments. Methods. We use in-situ synchrotron X-ray powder diffraction to obtain detailed structural data pertaining to the formation of the crystalline calcium carbonate phase vaterite and its evolution with temperature. Results. We found that the metastable calcium carbonate phase vaterite was formed alongside calcite, at elevated CO2 pressure, at room temperature and subsequently remained stable over a large range of temperature and pressure. Conclusions. We report the formation of the calcium carbonate mineral vaterite whilst attempting to simulate carbonate dust grain formation in astrophysical environments. This suggests that vaterite could be a mineral component of carbonate dust and also presents a possible method of formation for vaterite and its polymorphs on planetary surfaces.

Journal Keywords: Calcium Carbonate; Planets; Dust; Astromineralogy

Subject Areas: Physics, Earth Science


Instruments: I11-High Resolution Powder Diffraction

Added On: 10/04/2013 10:23

Discipline Tags:

Earth Sciences & Environment Mineralogy Physics Geology Planetary Geology Astronomy & Astrophysics

Technical Tags:

Diffraction X-ray Powder Diffraction