Discovery of new mineral addibischoffite, Ca_2Al_6Al_6O_(20) ,IN A Ca-Al-Rich refractory inclusion from the Acfer 214 CH3 meteorite

Introduction: During a mineralogy investigation of the Acfer 214 CH3 carbonaceous chondrite, a new calcium aluminate mineral, named “addibischoffite”, Ca_2Al_6Al_6O_(20) with the P-1 aenigmatite structure, was identified in a Ca-Al-rich inclusion (CAI). Field-emission scanning electron microscope, electron back-scatter diffraction, electron microprobe and ion microprobe were used to characterize its chemical and oxygen-isotope compositions, structure, and associated phases. Synthetic CaAl_6O_(10) was reported but not fully characterized [e.g., 1]. Presented here is its first natural occurrence as a new refractory mineral in a primitive meteorite. The mineral has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2015-006). The name is in honor of Addi Bischoff, a cosmochemist at Münster University, Germany, for his many contributions to research on CAIs in carbonaceous chondrites, including CH chondrites

Boron enrichment in Martian clay

We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration

Discovery of new mineral addibischoffite, Ca_2Al_6Al_6O_(20) ,IN A Ca-Al-Rich refractory inclusion from the Acfer 214 CH3 meteorite

Introduction: During a mineralogy investigation of the Acfer 214 CH3 carbonaceous chondrite, a new calcium aluminate mineral, named “addibischoffite”, Ca_2Al_6Al_6O_(20) with the P-1 aenigmatite structure, was identified in a Ca-Al-rich inclusion (CAI). Field-emission scanning electron microscope, electron back-scatter diffraction, electron microprobe and ion microprobe were used to characterize its chemical and oxygen-isotope compositions, structure, and associated phases. Synthetic CaAl_6O_(10) was reported but not fully characterized [e.g., 1]. Presented here is its first natural occurrence as a new refractory mineral in a primitive meteorite. The mineral has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2015-006). The name is in honor of Addi Bischoff, a cosmochemist at Münster University, Germany, for his many contributions to research on CAIs in carbonaceous chondrites, including CH chondrites

The isotopic composition and fluence of solar-wind nitrogen in a genesis B/C array collector

We have measured the isotopic composition and fluence of solar-wind nitrogen in a diamond-like-carbon collector from the Genesis B/C array. The B and C collector arrays on the Genesis spacecraft passively collected bulk solar wind for the entire collection period, and there is no need to correct data for instrumental fractionation during collection, unlike data from the Genesis “Concentrator.” This work validates isotopic measurements from the concentrator by Marty et al. (2010, 2011); nitrogen in the solar wind is depleted in ^(15)N relative to nitrogen in the Earth’s atmosphere. Specifically, our array data yield values for ^(15)N/^(14)N of (2.17 ± 0.37) × 10^(−3) and (2.12 ± 0.34) × 10^(−3), depending on data-reduction technique. This result contradicts preliminary results reported for previous measurements on B/C array materials by Pepin et al. (2009), so the discrepancy between Marty et al. (2010, 2011) and Pepin et al. (2009) was not due to fractionation of solar wind by the concentrator. Our measured value of ^(15)N/^(14)N in the solar wind shows that the Sun, and by extension the solar nebula, lie at the low-^(15)N/^(14)N end of the range of nitrogen isotopic compositions observed in the solar system. A global process (or combination of processes) must have operated in interstellar space and/or during the earliest stages of solar system formation to increase the ^(15)N/^(14)N ratio of the solar system solids. We also report a preliminary Genesis solar-wind nitrogen fluence of (2.57 ± 0.42) × 10^(12) cm^(−2). This value is higher than that derived by backside profiling of a Genesis silicon collector (Heber et al. 2011a)

Discovery of Warkite, Ca_2Sc_6Al_6O_(20), a New Sc-Rich Ultra-Refractory Mineral in Murchison and Vigarano

Scandium has an inherent but underutilized potential for constraining environments and processes in the early solar system because it occurs at modest to high concentrations in a wide variety of refractory and ultra-refractory phases in chondritic meteorites. As a first step towards realizing some of Sc’s potential, we have been conducting nanomineralogy investigations of carbonaceous chondrites to characterize Sc-rich phases and their petrographic context. Here, we describe a new scandium aluminate mineral, Ca_2Sc_6Al_6O_(20) with a P-1 aenigmatite-type structure, in ultra-refractory inclusions from the Murchison CM2 and Vigarano CV3 chondrites [1]. Based on EPMA, a previously reported phase in the CH chondrite Acfer 182 [2] provides an-other example. The Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association has approved this mineral (IMA 2013-129) [3], the name, war-kite, in honor of David Wark (1939-2005) for his many contributions to research on Ca-Al-rich inclusions

Discovery of Rubinite, Ca_3Ti^(3+)_2Si_3O_(12), a new Garnet Mineral in Refractory Inclusions from Carbonaceous Chondrites

During a nanomineralogy investigation of carbonaceous chondrites, a new Ti^(3+)-dominant garnet, named “rubinite,” Ca_3Ti^(3+)_2Si_3O_(12) with the Ia^3d garnet structure, was identified in five Ca-Al-rich inclusions (CAIs) from the CV3 chondrites Vigarano, Allende, and Efremovka. Field-emission scanning electron microscope, electron back-scatter diffraction, electron microprobe and ion microprobe techniques were used to characterize the chemistry, oxygen-isotope compositions, and structure of rubinite and associated phases. Synthetic Ca_3Ti^(3+)_2Si_3O_(12) garnet was reported by [1]. Here, we describe the first natural occurrences of rubinite as a refractory mineral in primitive meteorites. The mineral has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2016-110) [2]. The name honors Alan E. Rubin, a cosmochemist at University of California, Los Angeles (UCLA), USA, for his many contributions to cosmochemistry and meteorite research