Raman investigations and ab initio calculations of natural diamond-lonsdaleite originating from New Caledonia

Here, we report the first occurrence so far of cubic diamond and lonsdaleite in a siliceous breccia hosted nickel laterite from Tiébaghi mine, New Caledonia. Diamond polytype occurred as minerals surficial formed rocks. The vibrational properties calculated elastic electronic band structure 3C-diamond were studied by micro-Raman spectroscopy ab initio calculation. Our measured Raman spectra demonstrate coexistence based on correlation between calculation experimental results. We showed that position single vibration mode for corresponds to order scattering F2g symmetry at 1332 cm−1. For lonsdaleite, calculations predict three fundamental modes: 1207 cm−1 (E2g), 1307 (A1g), 1330 (E1g). indirect bandgaps room temperature are 5.7 eV 5.2 eV, respectively. anisotropy show has greatest shear modulus, bulk modulus young’s compared diamond, which indicates high degree hardness this hexagonal diamond.