Four Treasures Reference Database
Record No. 2052
Das Phasenkontrast-Verfahren nach Zernike zur Untersuchung von Inhomogenitäten in Edelsteinen
The phase contrast method according to Zernike for the examination of inhomogeneities in gemstones
Journal Article
Gübelin, E.J. (1957) Das Phasenkontrast-Verfahren nach Zernike zur Untersuchung von Inhomogenitäten in Edelsteinen. [The phase contrast method according to Zernike for the examination of inhomogeneities in gemstones] Zeitschrift der Deutschen Gesellschaft für Edelsteinkunde, (Festschrift zur Vollendung des 70. Lebensjahres von Professor Dr. Schlossmacher), No. 20, Summer, pp. 43–52.
Sinkankas/Born No.: NIS / NIB | Language: in German | not seen
phase-contrast microscopy, gems
Explains the application of Zernike’s phase contrast microscopy to reveal subtle internal features in gemstones. By converting differences in optical path into visible brightness contrasts, the method enhances thin, transparent inclusions and structures whose refractive indices closely resemble those of their hosts. Specially adapted equipment permits examination within gemstones, revealing exsolution, alteration and healed fractures that are difficult to distinguish under ordinary illumination.