Organic inclusions evidence, composition, and cathodoluminescence behaviour for the formation conditions of fluorapatite from Anemzi (Morocco)

Abstract

Fluorapatite from Anemzi alkaline syenite hosts a wealth of solid organic inclusions, mainly of aliphatic (2,935–2,845 cm−1) and aromatic hydrocarbon compositions (3,100–3,000 cm−1), as well as traces of bituminous matter showing a low degree of ordering. The tiny inclusions built from oxides of titanium (rutile and anatase) are the only mineral phases found in host crystals. The two‐phase, liquid–gas fluid inclusions are composed of aliphatic and aromatic functional groups, revealing bands in the region 1,600–1,200 cm−1. A slightly chemically varied composition and blue, homogenous cathodoluminescence colours, activated mainly by Ce3+, as well as a small volume of mineral inclusions in apatite, indicate that its crystallization, as influenced by hydrocarbon‐ and carbonaceous matter‐bearing fluids, proceeded under stable environmental conditions. It is probable that these fluids were migrated within the adjacent carbonate rocks found in the vicinity of alkaline syenites, which could be the source of organic components entrapped by apatite. A numerous assemblage of organic inclusions is diagnostic feature for gem quality green apatite from Anemzi.

Blue or green? turquoise–planerite species from Carico Lake Valley in Nevada, the United States: Evidence from Raman spectroscopy

“…The analytical materials seem to contain a significant amount of organic inclusions (Figure , Table S4), the presence of which is confirmed by the bands ca 1590 and 2899 cm ‐1 due to C=C and C‐H stretching vibrations, respectively …”

“…Similar observations were made [22,23] 216 Cu 2 O ? [24] 248 Al 2 O 3 [18,22] 284 CuO [18,25] 315 Fe-O sym, Al-(O,OH,H 2 O) [10,18,26,27] 354 Fe-O sym, Al-(O,OH,H 2 O) [10,18,26,27] 443 ν 2 symmetric bending vibrations of HPO 4 2and PO 4 3-, [10,18,20] 485 Fe-O [26] [10,16,20,22] 631 CuO [25] 662 Fe-O sym str. (goethite), Si-O/Al-O [26,28] 783 Si-O/Al-O [28] 768 ν 4 bending vibrations of CO 3 2 [16] 813 Al 2 O 3 , Si-O [17,22,28] 874 hydroxyl deformation [10,18] 930 hydroxyl deformation [10,18] by Reddy et al, [12] who investigated blue species from Arizona and green one from Senegal with ultravioletvisible, near-infrared, and mid-infrared reflectance spectroscopy.…”

“…The analytical materials seem to contain a significant amount of organic inclusions (Figure 4, Table S4), the presence of which is confirmed by the bands ca 1590 and 2899 cm -1 due to C=C and C-H stretching vibrations, respectively. [20,21] Both blue and green varieties of phosphate were also excited with a 442-nm laser to measure their characteristic Raman spectra. The maximum of the dominant peak appears at approximately 1040 cm -1 , and contribution of the component peaks in this band differs for both colour varieties ( Table 2), indicating the probably resonant enhancement of this vibration.…”

“…[22,23] Blue phosphate is characterized by structurally sensitive bands of 216, 248, and 284 cm -1 , indicating the presence of copper oxides, [18,22,25] and a 1009-cm -1 band for ν 3 HPO 4 2. [10,20]…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

“…Dumanska‐Slowik and co‐workers described organic inclusions evidence, composition, and cathodoluminescence behaviour for the formation conditions of fluorapatite from Anemzi (Morocco). They found that a numerous assemblage of organic inclusions is a diagnostic feature for gem quality green apatite from Anemzi . Kotnana investigated spin–phonon coupling in HoCr 1−x Fe x O 3 (x = 0 and 0.5) compounds .…”