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chromophores

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Journal Article
Published: 01 December 2011
European Journal of Mineralogy (2011) 23 (6): 969-980.
...) and from Catania Roman amphitheatre, were studied by XANES, UV-VIS and luminescence spectroscopies to determine the distribution of the oxidation states of the two chromophores Fe and Mn. The samples, characterized by different colour nuances, were previously chemically characterized. In all the ancient...
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Journal Article
Published: 01 December 2006
Mineralogical Magazine (2006) 70 (6): 669-687.
... corundum deposits are compared to consider their origins. Sapphires from Weldborough, NE Tasmania, are magmatic (high-Ga, av. 200 ppm) and dominated by Fe (av. 3300 ppm) and variable Ti (av. 400 ppm) as chromophores. They contain Cl, Fe, Ga, Ti and CO 2 -rich fluid inclusions and give δ 18 O values (5.1...
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Journal Article
Published: 01 July 2017
The Canadian Mineralogist (2017) 55 (4): 561-593.
... emerald. Using field relationships, Ar-Ar dating, whole-rock geochemistry, stable isotopes (O, H, C, and B), and mineral chemistry, the sources of the emerald-forming fluids and chromophores have been assessed; the results clearly show that the ca . 100 Ma (Ar-Ar muscovite) Lened emerald occurrence...
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Journal Article
Published: 03 February 2015
The Canadian Mineralogist (2015) 52 (5): 809-836.
... and dimensions of the unit cell parameters of beryl from ten pegmatites from the Velasco district were used to identify differences among beryl types, determine chromophore elements, and determine the relative degree of fractionation of the pegmatites. Concentrations of Rb, Li, Cs, and Na in all beryls analyzed...
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Journal Article
Published: 01 August 2003
Mineralogical Magazine (2003) 67 (4): 717-732.
....% Cr 2 O 3 ) as the main chromophore, exceeding Fe (up to 0.5 wt.%Fe 2 O 3 ). Corrosive etching suggests a prior xenocrystic Mesozoic-Cenozoic basaltic transport, while Cr 2 O 3 /Ga 2 O 3 to Fe 2 O 3 /TiO 2 ratios indicate an original metamorphic source. Syngenetic mineral inclusions include Al-rich...
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Journal Article
Published: 01 October 2002
The Canadian Mineralogist (2002) 40 (5): 1313-1338.
... in length occur in tourmaline zones and, rarely, in the quartz veins. Some of the smaller crystals, and sections of larger crystals, are of gem quality. The Cr content (average 3208 ppm) shows that it is the predominant chromophore. Fluid-inclusion data indicate that the emerald precipitated from a fluid...
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Journal Article
Journal: Clay Minerals
Published: 01 June 2001
Clay Minerals (2001) 36 (2): 263-266.
...M. OGAWA; M. YAMAMOTO; K. KURODA Abstract Intercalation of an ammonium amphiphile having an azobenzene chromophore, 4-dodecyloxy-4′-(trimethylammoniopentyloxy)azobenzene and 4-(ω-trimethylammoniodecyloxy)-p′-(octyloxy)azobenzene bromide, into the layered silicate magadiite (ideal formula Na 2 Si 14...
FIGURES
Image
a) Resonance Raman spectrum of sulphur <b>chromophore</b> under green laser excita...
Published: 01 December 2013
Fig. 1 a) Resonance Raman spectrum of sulphur chromophore under green laser excitation; b) plot of the S 3 − 545 cm −1 peak intensity vs. the energy values of the lasers used to obtain the spectra: the maximum is measured for green excitation; the spectrum intensity has been normalized
Image
Weight proportions of free major emerald <b>chromophore</b> oxides in the composit...
Published: 01 April 2006
F ig . 4. Weight proportions of free major emerald chromophore oxides in the composition of Delbegetey emeralds (based on 35 microprobe analyses of ten samples).
Journal Article
Published: 01 February 1996
European Journal of Mineralogy (1996) 8 (1): 25-34.
Journal Article
Published: 01 August 2017
American Mineralogist (2017) 102 (8): 1747-1758.
... sample, and chromophore concentrations. The use of the techniques outlined here can lead to a better understanding of the color sciences in the mineral world in general. The chemical composition of the synthetic alexandrite was also measured at Caltech on a JEOL JXA-8200 electron microprobe...
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Journal Article
Published: 01 July 2017
The Canadian Mineralogist (2017) 55 (4): 799-820.
... and vanadium are the main chromophores, and the highest concentrations (1240 and 400 ppm, respectively) were found in deep blue-colored zones. Surprisingly, the euclase crystals have high Ge contents, between 230 and 530 ppm. The Rare Earth Element (REE) patterns of euclase are inherited from the enclosed BS...
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Journal Article
Journal: Clay Minerals
Published: 01 March 2017
Clay Minerals (2017) 52 (1): 83-95.
...R.A. Menezes; S.P.A. Paz; R.S. Angélica; R.F. Neves; R. Neumann; F.R.L. Faulstich; S.B.C. Pergher Abstract Ultramarine pigments were synthesized successfully from Na-A zeolite derived from kaolin waste. Na-A zeolite encapsulates the sulfur species formed and which act as chromophores, which...
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Journal Article
Published: 01 August 2016
Mineralogical Magazine (2016) 80 (5): 705-718.
... additive colours coming through the windows of transparency. A dark-green chromium-bearing tourmaline from the Ural Mountains (0.40 and 0.20 apfu Cr and Fe, respectively) shows how admixtures of other chromophore ions, namely, Fe 2+ and Fe 3+ , can suppress the Usambara effect in tourmaline. * E-mail...
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Journal Article
Published: 01 June 2016
European Journal of Mineralogy (2016) 28 (3): 571-580.
..., as shown by comparison with literature data. In particular, the quantification of Mn confirmed a direct correlation between the concentration of this chromophore element and the red colour saturation of the samples. * Corresponding author, e-mail: gioacchino.tempesta@uniba.it 13 11 2015 12...
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Journal Article
Published: 01 June 2016
South African Journal of Geology (2016) 119 (2): 359-378.
.... The major and minor element chemistry of the emeralds are broadly similar to other emerald deposits world-wide. The major chromophore appears to be Cr as opposed to V. Na contents are somewhat higher than the world-wide average and this, along with the inclusion suite, could serve to distinguish...
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Journal Article
Published: 01 November 2014
American Mineralogist (2014) 99 (11-12): 2187-2195.
... chromophores below the detection limit of electron microprobe may participate to light absorption. All this information contribute to the comprehension of the causes of crystal color of minerals, gemstones, and ceramic pigments. * E-mail: rosaanna.fregola@uniba.it Manuscript handled by Kristina...
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Journal Article
Journal: Clay Minerals
Published: 01 June 2011
Clay Minerals (2011) 46 (2): 189-195.
... sizes (mainly H-ZSM-5, H-mordenite), the natural zeolites did not form products with an intense (pink) colouration. H-mordenite samples treated with styrene developed some colour due to styrene oligomers (the chromophore) whereas, in treated clinoptilolites, colour formation was negligible due...
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Journal Article
Published: 01 February 2011
The Canadian Mineralogist (2011) 49 (1): 301-319.
... tourmaline, all have elevated TiO 2 (average 0.28 wt.%). The absence of other chromophoric elements suggests that the yellow to yellow-green coloration is due to a Mn 2+ –Ti 4+ intervalence charge-transfer interaction, which is consistent with earlier spectroscopic studies. Increasing Fe content...
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Journal Article
Published: 01 January 2011
European Journal of Mineralogy (2011) 23 (1): 91-100.
... to ~1.0 wt%. This chromophore element, if present, influences the garnet’s colour, which is mainly due to Fe 3+ . The Cr-content does not affect the unit-cell constant, at least within the range found here. The refined electron content at the Fe-site suggests that chromium occupies the octahedral site...
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