• DOI:10.1126/science.1232139
• Corpus ID: 206546317

Vaterite Crystals Contain Two Interspersed Crystal Structures

@article{KabalahAmitai2013VateriteCC,
  title={Vaterite Crystals Contain Two Interspersed Crystal Structures},
  author={Lee Kabalah-Amitai and Boaz Mayzel and Yaron Kauffmann and Andrew N. Fitch and Leonid Bloch and Pupa U.P.A. Gilbert and Boaz Pokroy},
  journal={Science},
  year={2013},
  volume={340},
  pages={454 - 457}
}

• Lee Kabalah-Amitai, B. Mayzel, +4 authors B. Pokroy
• Published 26 April 2013
• Materials Science, Geology
• Science

Double Vision Vaterite is the least stable form of anhydrous crystalline calcium carbonate. While rarely found in geological contexts, it is an important biological precursor and occurs as a minor component in the shells of some organisms. The crystal structure of vaterite has long been debated with no model able to explain all the experimentally observed diffraction spots. Kabalah-Amitai et al. (p. 454) show that vaterite contains two coexisting crystallographic structures that form a pseudo-single crystal. Electron microscopy reveals that vaterite, a calcium carbonate polymorph, comprises at least two distinct crystal structures. Calcite, aragonite, and vaterite are the three anhydrous polymorphs of calcium carbonate, in order of decreasing thermodynamic stability. Although vaterite is not commonly found in geological settings, it is an important precursor in several carbonate-forming systems and can be found in biological settings. Because of difficulties in obtaining large, pure, single crystals, the crystal structure of vaterite has been elusive for almost a century. Using aberration-corrected high-resolution transmission electron microscopy, we found that vaterite is actually composed of at least two different crystallographic structures that coexist within a pseudo–single crystal. The major structure exhibits hexagonal symmetry; the minor structure, existing as nanodomains within the major matrix, is still unknown.