Jump to ContentJump to Main Navigation
Show Summary Details
More options …

American Mineralogist

Journal of Earth and Planetary Materials

Ed. by Putirka, Keith / Swainson, Ian

12 Issues per year


IMPACT FACTOR 2016: 2.021

CiteScore 2016: 1.88

SCImago Journal Rank (SJR) 2016: 0.952
Source Normalized Impact per Paper (SNIP) 2016: 0.955

Online
ISSN
1945-3027
See all formats and pricing
More options …
Volume 100, Issue 10 (Oct 2015)

Issues

Decagonite, Al71Ni24Fe5, a quasicrystal with decagonal symmetry from the Khatyrka CV3 carbonaceous chondrite

Luca Bindi
  • Corresponding author
  • Dipartimento di Scienze della Terra, Università di Firenze, Via La Pira 4, I-50121 Florence, Italy
  • Email
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Nan Yao
  • Princeton Institute for the Science and Technology of Materials, Bowen Hall, Princeton University, Princeton, New Jersey 08544, U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Chaney Lin / Lincoln S. Hollister
  • Department of Geosciences, Princeton University, Guyot Hall, Princeton, New Jersey 08544, U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Christopher L. Andronicos
  • Division of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47907, U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Vadim V. Distler
  • Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (IGEM), Russian Academy of Sciences, Staromonetny per. 35, Moscow, 119017, Russia
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Michael P. Eddy
  • Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Alexander Kostin / Valery Kryachko
  • Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (IGEM), Russian Academy of Sciences, Staromonetny per. 35, Moscow, 119017, Russia
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Glenn J. MacPherson
  • Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560, U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ William M. Steinhardt
  • Dipartimento di Scienze della Terra, Università di Firenze, Via La Pira 4, I-50121 Florence, Italy
  • Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, Massachusetts 02138, U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Marina Yudovskaya
  • Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (IGEM), Russian Academy of Sciences, Staromonetny per. 35, Moscow, 119017, Russia
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Paul J. Steinhardt
  • Department of Physics, Princeton University, Jadwin Hall, Princeton, New Jersey 08544, U.S.A.
  • Dipartimento di Scienze della Terra, Università di Firenze, Via La Pira 4, I-50121 Florence, Italy
  • Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544 U.S.A.
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2015-09-30 | DOI: https://doi.org/10.2138/am-2015-5423

Abstract

Decagonite is the second natural quasicrystal, after icosahedrite (Al63Cu24Fe13), and the first to exhibit the crystallographically forbidden decagonal symmetry. It was found as rare fragments up to ~60 mm across in one of the grains (labeled number 126) of the Khatyrka meteorite, a CV3 carbonaceous chondrite. The meteoritic grain contains evidence of a heterogeneous distribution of pressures and temperatures that occurred during impact shock, in which some portions of the meteorite reached at least 5 GPa and 1200 °C. Decagonite is associated with Al-bearing trevorite, diopside, forsterite, ahrensite, clinoenstatite, nepheline, coesite, pentlandite, Cu-bearing troilite, icosahedrite, khatyrkite, taenite, Al-bearing taenite, and steinhardtite. Given the exceedingly small size of decagonite, it was not possible to determine most of the physical properties for the mineral. A mean of seven electron microprobe analyses (obtained from three different fragments) gave the formula Al70.2(3)Ni24.5(4)Fe5.3(2), on the basis of 100 atoms. A combined TEM and single-crystal X‑ray diffraction study revealed the unmistakable signature of a decagonal quasicrystal: a pattern of sharp peaks arranged in straight lines with 10-fold symmetry together with periodic patterns taken perpendicular to the 10-fold direction. For quasicrystals, by definition, the structure is not reducible to a single three-dimensional unit cell, so neither cell parameters nor Z can be given. The likely space group is P105/mmc, as is the case for synthetic Al71Ni24Fe5. The five strongest powder-diffraction lines [d in Å (I/I0)] are: 2.024 (100), 3.765 (50), 2.051 (45), 3.405 (40), 1.9799 (40). The new mineral has been approved by the IMA-NMNC Commission (IMA2015-017) and named decagonite for the 10-fold symmetry of its structure. The finding of a second natural quasicrystal informs the longstanding debate about the stability and robustness of quasicrystals among condensed matter physicists and demonstrates that mineralogy can continue to surprise us and have a strong impact on other disciplines.

Keywords: Quasicrystal; aluminum; meteorite; chemical composition; TEM; X‑ray diffraction; new mineral; decagonite

Keywords: Quasicrystal; aluminum; meteorite; chemical composition; TEM; X‑ray diffraction; new mineral; decagonite

About the article

Received: 2015-05-16

Accepted: 2015-05-28

Published Online: 2015-09-30

Published in Print: 2015-10-01


Citation Information: American Mineralogist, ISSN (Online) 1945-3027, ISSN (Print) 0003-004X, DOI: https://doi.org/10.2138/am-2015-5423.

Export Citation

© 2015 by Walter de Gruyter Berlin/Boston.

Comments (0)

Please log in or register to comment.
Log in