Publication
Reference
Ferrari M., De Angelis S., De Sanctis M.~C., Ammannito E., Stefani S., Piccioni G. (2019). Reflectance spectroscopy of ammonium-bearing phyllosilicates. Icarus, 321, 522 - 530.
Names
  • M. Ferrari
  • S. De Angelis
  • M.~C. De Sanctis
  • E. Ammannito
  • S. Stefani
  • G. Piccioni
Article and keywords
Title
Reflectance spectroscopy of ammonium-bearing phyllosilicates
Abstract
The identification of NH$_4$-bearing phyllosilicates on Ceres poses the question on the NH$_4$-carrier phase(s) and in this study we describe the laboratory production and IR spectroscopic measurements of a suite of ten NH$_4$-phyllosilicates, starting from the corresponding NH$_4$-free minerals. For each mineral, we prepared three types of powder samples: raw (R), ammoniated (A), and leached (L). All samples have been spectrally characterized by means of visible/infrared spectroscopy in the INAF-IAPS laboratories with the FieldSpec Pro in the 0.35-2.5 \ensuremathμm range, and with the FT-IR, using a Vertex 80 spectrometer operating in the range of 2-14 \ensuremathμm. The samples were also measured with the SPectral IMager, an imaging spectrometer operating in the spectral range 0.2-5.1 \ensuremathμm, which is a replica of the VIR spectrometer on-board Dawn spacecraft. Reflectance spectra of the ammoniated clays show bands near 1.56 \ensuremathμm, 2.05 \ensuremathμm, 2.12 \ensuremathμm, 3.06 \ensuremathμm, 3.25 \ensuremathμm, 3.55 \ensuremathμm, 4.2 \ensuremathμm, 5.7 \ensuremathμm and 7.0 \ensuremathμm that are related to the presence of nitrogen complexes. Treatment of phyllosilicates with ammonia shows that different minerals behave in different ways: NH$_4^+$ ions are easily accepted by the smectites, while other non-expandable structures do not accept these ions. The obtained results can be used to better constrain the NH$_4$-bearing species present on Ceres and, possibly, other bodies of the solar system.
Keywords
spectroscopy, bidirectional reflectance spectra, visible, near-IR, mid-IR, ammoniated clays, phyllosilicate, nontronite, sepiolite, illite, montmorillonite, rectorite, hectorite, biotite, serpentine, smectite, asteroid, Ceres
Content
spectral data, spectral data use, planetary sciences
Year
2019
Journal
Icarus
Volume
321
Pages
522 - 530
Pages number
9
Document type
article
Publication state
published
Doi
10.1016/j.icarus.2018.11.031
Identifiers