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Updated: Jul 12, 2026

Negative Additive Manufacturing of Complex Shaped Boron Carbides
Published on: September 18, 2018
A new allotropic form of carbon from the ries crater
Abstract:
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 angstroms, with a primitive hexagonal lattice.
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