Microdiamonds from UHP metamorphic rocks of the Kokchetav Massif, northern Kazakhstan: FTIR spectroscopy, C & N isotopes and morphology - De Corte, K.; Cartigny, P.; Shatsky, V.S.; De Paepe, P.; Sobolev, N.V.; Javoy, M. (International Kimberlite Conference: Extended Abstracts, 1998)