- journal_title：European Journal of Mineralogy
- Contributor：Michail N. TARAN ; Victor M. KVASNYTSYA ; Klaus LANGER
- Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
- Date：2004-
- Format：text/html
- Language：en
- Identifier：10.1127/0935-1221/2004/0016-0241
- journal_abbrev：Eur J Mineral
- issn：0935-1221
- volume：16
- issue：2
- firstpage：241
- section：Articles
A distinctive feature of Ukrainian deep-violet diamond microcrystals is a broad absorption band centered at about 560 nm (17850 cm−1 or 2.21 eV). In the Ukrainian samples, the intensity of this band is almost two orders of magnitude greater than in a light-rose diamond from Yakutia. Previously (Taran et al., 1998), the band was attributed to the N-V center because the absorption spectrum of the negative N-V center in irradiated and annealed type Ib diamonds is known to have an absorption band with a maximum at a similar wavelength. However, this assignment is not confirmed by vibrational spectroscopy and low temperature optical absorption spectroscopy in all crystals studied. In addition, at ∼77 K the band 17850 cm−1 displays no fine structure that unambiguously evidences that it can not be the band at ∼2.2 eV, commonly attributed to the N-V center.