A New Allotropic Form of Carbon from the Ries Crater

  title={A New Allotropic Form of Carbon from the Ries Crater},
  author={Ahmed El Goresy and Guy Donnay},
  pages={363 - 364}
A new allotropic form of carbon occurs in shock-fused graphite gneisses in the Ries Crater, Bavaria. The assemblage in which it occurs consists of hexagonal graphite, rutile, pseudobrookite, magnetite, nickeliferous pyrrhotite, and baddeleyite. Electron-probe analyses indicate that the new phase is pure carbon. It is opaque and much more strongly reflecting than hexagonal graphite. Measurement of x-ray diffraction powder patterns leads to cell dimensions a = 8.948 � 0.009, c = 14.078 � 0.017… 

Carbon: Observations on the New Allotropic Form

The recently characterized " white " allotropic form of carbon has been produced at high temperature and low pressure during graphite sublimation and the interplanar spacings are identical to those of a carbon form noted in graphitic gneiss from the Ries Crater.

The nature of metastable phases of carbon

THE following forms of carbon are already known: rhombohedral and hexagonal graphite, diamond, lonsdailite, carbines, Ries crater carbon, and metallic carbon. We describe here new metastable phases


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  • C. Pillinger
  • Physics, Geology
    Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences
  • 1993
C60 has not yet been detected in primitive meteorites, a finding that could demonstrate its existence in the early solar nebular or as a component of presolar dust. However, other allotropes of

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Abstract— Since their discovery, fullerenes have been reported from various geological environments. One group of these findings has been related to bolide impacts, e.g., the Sudbury crater and the

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Carbon has the widest variety of allotropes, namely, diamond has a threedimensional structure, graphite has a quasi-two-dimensional structure and fullerene as a giant molecule is zero-dimensional.

Carbynes in Meteorites: Detection, Low-Temperature Origin, and Implications for Interstellar Molecules

Although carbynes have been known to form only by condensation of carbon vapor above 2600 K or by explosive shock of > 600 kilobars, it is found that they also form metastably by the reaction 2CO → CO2 + C (solid) at 300� to 400�C in the presence of a chromite catalyst.



Symbols: D, displacement of pendulum barrier

    end-effect correction for displacement