Olivine Nephelinite,Tephrite,Essexite,Phonolite,and Tinguaite from Kaiserstuhl,Germany:Evidence From Melt Inclusions in Pyroxene

摘要

Electron spin resonance (ESR) and cathodoluminescence (CL) evidence on diamonds from the Peo-ples Republic of China is reported. In addition to paramagnetic centers P1 and P2 that had been observed in China diamonds, the W7, W21, N2, OKI, and 01 centers were identified by ESR spectra for the set of samples studied. The last two centers are regarded as oxygen-bearing. In the CL spectra, in addition to broad bands at 440 and 530 nm (the latter being related to boron centers), narrow bands were observed at 503 nm with phonon repetitions (H3 center), 415 nm (P2 ESR center), 575 nm, and 490.7 nm, as well as broad peaks at 720 and 920 nm. Characteristic narrow peaks were frequent on the background of the 720-nm broad peak; their appearance in synthetic diamond is assigned to the presence of nickel. An analysis of the appearance and behavior of the centers that are observable in ESR and CL spectra showed a correlation between the type of defect, its concen-tration, and abundance, on one hand, and the crystal morphology, mineralogy, and geochemistry of the dia-mond, on the other. The ESR and CL characteristics of diamonds from various China deposits provide grounds to believe that the combination of these parameters would aid in distinguishing diamonds from different pipes. In some cases, this spectroscopic evidence would substantially revise the prior genetic and geochemical ideas that were based on IR spectra and CL patterns only and would make them more exact.