Pyroxferroite: Stability and X-ray Crystallography of Synthetic Ca0.15Fe0.85SiO3 Pyroxenoid

@article{Lindsley1970PyroxferroiteSA,
  title={Pyroxferroite: Stability and X-ray Crystallography of Synthetic Ca0.15Fe0.85SiO3 Pyroxenoid},
  author={Donald H. Lindsley and Charles W. Burnham},
  journal={Science},
  year={1970},
  volume={168},
  pages={364 - 367}
}
Synthetic Ca0.15Fe0.85SiO3 pyroxenoid has the same (pyroxmangite) structure and very nearly the same composition as pyroxferroite, a new mineral found in Apollo 11 lunar samples. The synthetic material is not stable below pressures of approximately 10 kilobars. It appears likely that the lunar pyroxferroite has persisted in a metastable state for some billions of years. 
Mössbauer spectra of synthetic Ca-Fe pyroxenoids and lunar pyroxferroite
Resolution of the iron sites in the Mössbauer spectra of Ca-Fe pyroxenoids is only partial, two doublets being apparent in each case, whereas there are up to nine cation sites in each structure. Thus
Transmission electron microscopy of synthetic and natural Fünferketten and Siebenerketten pyroxenoids
A new type of fault, called a chain periodicity fault, has been observed in Fünferketten and Siebenerketten pyroxenoids. The faults are mainly parallel to (001) and are due to irregularities in the
Pyroxmangite: A high-pressure single-crystal study
Abstract We present the results of a single-crystal X-ray diffraction structural study on pyroxmangite in a diamond-anvil cell up to 5.6 GPa. The sample comes from Yokone-Yama, Awano Town, Tochigi
Crystal Chemistry of Silicate Minerals of Geophysical Interest
Recent crystal chemical research on rock-forming silicate minerals has focused on the accurate refinement of room temperature and high-temperature crystal structures. The data are of sufficient
Reaction sequences, polysomatic faults and chemical compositions of manganese pyroxenoids from Campiglia Marittima skarn
The late crystallisation stages of Campiglia Marittima skarn are characterised by an increase in Mn-activity at the meta-somatic front. Mn-pyroxenoids became stable with respect to johannsenite. The
Phase relations inferred from field data for mn pyroxenes and pyroxenoids
Electron microprobe analysis of manganese silicates from Balmat, N.Y., has helped elucidate phase relations for Mn-bearing pyroxenes and pyroxenoids. A compilation of these data along with published
Pyroxenoids of pyroxmangite–pyroxferroite series from xenoliths of Bellerberg paleovolcano (Eifel, Germany): Chemical variations and specific features of cation distribution
The pyroxferroite and pyroxmangite from xenoliths of aluminous gneisses in the alkaline basalts of Bellerberg paleovulcano (Eifel, Germany) have been studied by electron-probe and X-ray diffraction
Symplectites derived from metastable phases in martian basaltic meteorites
Abstract The martian basalts Los Angeles, QUE 94201, Shergotty, and Zagami contain several late-stage mineral types including oxides, sulfides, phosphates, and associated silicate assemblages.
...
...

References

SHOWING 1-10 OF 20 REFERENCES
Ferrosilite III: A Triclinic Pyroxenoid-Type Polymorph of Ferrous Metasilicate
The relationships between the triclinic unit cell of ferrosilite III and those of pyroxmangite, rhodonite, and wollastonite lead to the hypothesis that this polymorph of ferrous metasilicate has a
Mineralogy and Deformation in Some Lunar Samples
TLDR
Overall homogeneity, igneous textures, and absence of xenoliths in the crystalline rocks indicate derivation from a common titanium-rich magma by internal, anorogenic volcanism rather than by impact.
Mineralogy and Composition of Lunar Fines and Selected Rocks
TLDR
Detailed descriptions are given of small craters produced by hypervelocity particle impact on glass and iron-nickel fragments in the fines and of surface rocks is attributed to mechanical ahrasion and not to cratering.
Electron-Microprobe Analyses of Phases in Lunar Samples
TLDR
Gross similarities between euctites and Apollo 11 volcanic rocks indiacate similar evolutionary environments, but detailed mineralogical differences suggest either separate origins or if eucrites are lunar, chemical inhomogeneities on the lunar surface.
Mineralogy and Petrography of Lunar Samples
TLDR
The lunar samples consist largely of augite, calcic plagioclase, and ilmenite, which resemble the calcium-rich achondritic meteorites (eucrites and howardites) in composition and structure.
Diffraction and M�ssbauer Studies of Minerals from Lunar Soils and Rocks
TLDR
In addition to identification of minerals, including rare amphibole, mica, and aragonite, a detailed study of the important rock-forming minerals of the plagioclase, pyroxene, and olivine groups has begun.
Petrologic History of Moon Suggested by Petrography, Mineralogy, and Crystallography
TLDR
Crystal-liquid differentiation of out-gassed convecting moon with growing Fe-rich core, olivine-pyroxene mantle, plagioclase-rich dynamic crust underlain by nonspherical, inversely stratified ferrobasalt is suggested.
Mineralogy and Petrology of Some Lunar Samples
Chemical analyses and norms of four samples are presented which confirm original estimates of low silica, unusual abundance of titania, and low oxidation state of the rocks. Accounts are given of
Petrology of Unshocked Crystalline Rocks and Shock Effects in Lunar Rocks and Minerals
On the basis of rock modes, textures, and mineralogy, unshocked crystalline rocks are classified into a dominant ilmenite-rich suite (subdivided into intersertal, ophitic, and hornfels types) and a
Age of the Moon: An Isotopic Study of Uranium-Thorium-Lead Systematics of Lunar Samples
TLDR
The fine dust and the breccia have a concordant age of 4.66 billion years on the basis of 207Pb/206Pb, 206PB/238U, 207P b/235U, and208Pb-232Th ratios, and six crystalline and vesicular samples are distinctly younger than the dust and Breccia.
...
...