Lonsdaleite, a Hexagonal Polymorph of Diamond

  title={Lonsdaleite, a Hexagonal Polymorph of Diamond},
  author={Clifford Frondel and Ursula B. Marvin},
TWO well known atomic arrangements found among tetrahedrally co-ordinated AX compounds such as silicon carbide (SiC) and zinc sulphide (ZnS) are those based on a cubic close-packed array or on a hexagonal close-packed array of tetrahedra. The two polymorphs are generally designated as the sphalerite and wurtzite types, respectively, from their occurrence in zinc sulphide. The crystal structures of the Group IV elements, carbon, silicon, germanium and α-tin, are based on the cubic close-packed… Expand
Nanocrystalline hexagonal diamond formed from glassy carbon
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Structural stability and the possible pathways to experimental formation of lonsdaleite—a hexagonal 2H polytype of diamond—have been studied in the framework of the density functional theory (DFT).Expand
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AbstractThe crystalline structure of diamond may consist of C8, C10 or C12 building units. C8 was regarded as the building block of the hexagonal diamond also known as Lonsdaleite. AdamantaneExpand
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Lonsdaleite is faulted and twinned cubic diamond and does not exist as a discrete material.
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This work proposes a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples. Expand
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Detailed optical studies of the textural features of several hundred diamonds and associated phases in three specimens of the Canyon Diablo meteorite and one specimen of the Novo Urei achondrite wereExpand
Critique of Paper by N. L. Carter and G. C. Kennedy, Origin of Diamonds in the Canyon Diablo
Carter and Kennedy claim to have found convincing evidence against a shock origin of meteoritic diamonds and suggest that they formed under high hydrostatic pressures instead. We have examined theirExpand