Nq. Dao et al., DISCOVERY OF DIAMOND INCLUSIONS IN RUBIES, Comptes rendus de l'Academie des sciences. Serie II. Mecanique, physique, chimie, astronomie, 322(6), 1996, pp. 515-522
Diamond and lonsdaleite, the hexagonal form of diamond, are discovered
together as inclusions in Vietnamese rubies by micro-Raman spectromet
ry. The presence of diamond crystal in the ruby matrix is confirmed by
X-ray diffraction using a 4-circle diffractometer. This is the first
time that such inclusions have been found in rubies.