A Raman investigation of the amblygonite-montebrasite series

Research areas:

• Surfaces planétaires (2011 - 2016)

Year:

2006

Authors:

• Benjamin Rondeau
• Emmanuel Fritsch
• Pierre LeFevre
• Michel Guiraud
• Andre-Mathieu Fransolet
• Yves Lulzac

Journal:

CANADIAN MINERALOGIST

Volume:

44

Number:

5

Pages:

1109-1117

Month:

October

ISSN:

0008-4476

BibTex:

@article{WOS:000241882100008, author = "Benjamin Rondeau and Emmanuel Fritsch and Pierre LeFevre and Michel Guiraud and Andre-Mathieu Fransolet and Yves Lulzac", abstract = "In order to obtain a more accurate method of identification of minerals of the amblygonite - montebrasite series, and particularly of gemstones cut from these minerals, we undertook an investigation by Raman spectroscopy, which is known to be a non-destructive method. Therefore, nine rough minerals and gemstones of the amblygonite-montebrasite series were analyzed by Raman spectroscopy, X-ray diffraction, infrared absorption spectroscopy, and the gemological properties (density and indices of refraction) of seven faceted gemstones were measured. Firstly, the Raman signal seems to be a good indicator of the fluorine content in the specimens, and thus useful for an accurate identification. Three peaks evolve significantly as F content increases: from 599 to 604 cm(-1), from 1056 to 1066 cm-1 and from 3379 to 3348 cm(-1). Also, the FWMH of the peak around 3370 cm(-1) increases from 11 to 57 cm(-1) as F content increases. Secondly, we found that all faceted gemstones studied herein consist of montebrasite and not amblygonite as usually claimed by gemstones traders.", doi = "10.2113/gscanmin.44.5.1109", extra = "PICL", issn = "0008-4476", journal = "CANADIAN MINERALOGIST", month = "OCT", number = "5", pages = "1109-1117", title = "{A} {R}aman investigation of the amblygonite-montebrasite series", volume = "44", year = "2006", }

Abstract:

In order to obtain a more accurate method of identification of minerals
of the amblygonite - montebrasite series, and particularly of gemstones
cut from these minerals, we undertook an investigation by Raman
spectroscopy, which is known to be a non-destructive method. Therefore,
nine rough minerals and gemstones of the amblygonite-montebrasite series
were analyzed by Raman spectroscopy, X-ray diffraction, infrared
absorption spectroscopy, and the gemological properties (density and
indices of refraction) of seven faceted gemstones were measured.
Firstly, the Raman signal seems to be a good indicator of the fluorine
content in the specimens, and thus useful for an accurate
identification. Three peaks evolve significantly as F content increases:
from 599 to 604 cm(-1), from 1056 to 1066 cm-1 and from 3379 to 3348
cm(-1). Also, the FWMH of the peak around 3370 cm(-1) increases from 11
to 57 cm(-1) as F content increases. Secondly, we found that all faceted
gemstones studied herein consist of montebrasite and not amblygonite as
usually claimed by gemstones traders.