1-20 OF 102 RESULTS FOR

pleochroism

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Journal Article
Published: 01 February 2025
American Mineralogist (2025) 110 (2): 328–335.
...Matthew J. Kohn Abstract Mineral separates mounted in thin section help introduce mineralogy students to concepts of relief, color, pleochroism, and birefringence and serve as reference materials both for research and teaching. Here, a simple method is described to produce materials that can...
FIGURES | View All (10)
Journal Article
Published: 11 October 2024
American Mineralogist (2024)
... density is 2.654 g·cm -3 . The Raman spectrum contains the following bands: 379, 357, 289, 236, 167, 131 and 124 cm -1 . In reflected light, the mineral has very strong pleochroism from yellow-pink to dark-grey. Anisotropy is very strong, ∆ R 589 = 69 %. Reflectance values for COM required wavelengths...
Journal Article
Published: 13 November 2023
Mineralogical Magazine (2024) 88 (1): 90–96.
FIGURES | View All (4)
Journal Article
Published: 03 January 2023
American Mineralogist (2023) 108 (1): 192–196.
...) (white light), and 2 V (calculated) = 83°. The dispersion is medium with r < v, and the pleochroism is with X = light brown, Y = brown, Z = dark brown. The color, streak, luster, and hardness (Mohs) are light brown, yellowish gray, vitreous, and 4½–5, respectively. Jingwenite-(Y) is monoclinic...
FIGURES | View All (4)
Journal Article
Published: 01 December 2022
American Mineralogist (2022) 107 (12): 2188–2200.
...-bearing plagioclase, as a function of particle size and shape, is also calculated from the computed extinction spectra. The colors and pleochroism observed in natural and treated Cu-bearing plagioclase can be explained from the computational results. The enigmatic green colors in some precious Oregon...
FIGURES | View All (12)
Journal Article
Published: 01 March 2022
American Mineralogist (2022) 107 (3): 489–494.
...Lætitia Gilles-Guéry; Laurence Galoisy; Jurgen Schnellrath; Benoit Baptiste; Georges Calas Abstract Pink euclase of gem quality and centimeter size, presenting an unusual pink-orange coloration and a pink to orange pleochroism, was discovered near Livramento de Nossa Senhora, in Bahia State, Brazil...
FIGURES | View All (5)
Journal Article
Published: 01 March 2020
Jour. Geol. Soc. India (2020) 95 (3): 279–285.
... grains show strong pleochroism from light greenish yellow to dark greenish brown and are highly fractured ( Fig. 3d ). Fig. 3. Petrography of pegmatite shows (a) Plagioclase grain showing zoning; (b) Granophyric texture at contact between perthetic Kfeldspar, plagioclase and quartz; (c...
FIGURES | View All (14)
Journal Article
Published: 01 September 2019
European Journal of Mineralogy (2019) 31 (5-6): 1025–1032.
.... It is transparent, green, with vitreous lustre. The calculated density ( D calc ) is 3.844 g cm −3 . Elasmochloite is optically uniaxial or pseudo-unixial (−), α = 1.611(2), β = γ = 1.698(2), 2 V ≈ 0°. Pleochroism is strong, Z ≈ Y (grass-green) > X (turquoise-blue). The chemical composition obtained by electron...
FIGURES | View All (6)
Journal Article
Published: 01 July 2019
European Journal of Mineralogy (2019) 31 (4): 775–784.
... microscopy (TEM), and its mineral chemistry has been investigated by means of wavelength-dispersive and TEM-based energy-dispersive spectrometry. In thin section, Fe-rich antigorite is characterized by a strong, peculiar pleochroism (α = green–dark green; γ = bright-yellow–orange). It occurs in both mesh...
FIGURES | View All (4)
Journal Article
Published: 01 May 2019
European Journal of Mineralogy (2019) 31 (3): 585–594.
... > v . The optical orientation is X = c , Y = a , Z = b . The pleochroism is X = yellow brown, Y = olive brown, Z = dark olive green; Z > Y > X . Crystal structure refinements on ferrirockbridgeite and other oxidized rockbridgeite-group species, including type rockbridgeite and type frondelite...
FIGURES | View All (7)
Journal Article
Published: 01 March 2019
European Journal of Mineralogy (2019) 31 (2): 389–397.
... = 1.781(calc), γ = 1.797(3) (white light) and 2 V (meas.) = 87(1)° from extinction data. The optical orientation is X = c , Y = a , Z = b . The pleochroism is X = blue green, Y = olive green, Z = yellow brown; X ≈ Y > Z . 21 08 2018 17 10 2018 18 10 2018 © 2018 E...
FIGURES | View All (11)
Journal Article
Published: 01 January 2019
European Journal of Mineralogy (2019) 31 (1): 167–172.
... cleavage parallel to {001} and Mohs’ hardness of about 4. The measured density is 2.89(2) g cm −3 . Optically, it is biaxial (+), with α = 1.655(2), β = 1.662(2), γ = 1.673(2) (white light); 2 V = 78(1)°; pleochroism: X nearly colourless, Y and Z beige; X < Y ≈ Z . Electron microprobe analyses gave...
FIGURES | View All (5)
Journal Article
Published: 01 January 2019
European Journal of Mineralogy (2019) 31 (1): 127–134.
..., the mineral dissolves rapidly in dilute HCl. Optically, manganflurlite is biaxial (–), with α = 1.623(calc), β = 1.649(2), γ = 1.673(2) (white light); 2 V = 86(1)°. The dispersion is r > v , slight; the optical orientation is X = c , Y = b , Z = a . The pleochroism is X = pale yellow brown, Y = orange...
FIGURES | View All (5)
Journal Article
Published: 23 October 2018
The Canadian Mineralogist (2018) 56 (4): 543–553.
... (+) and has a 2 V angle of ≅ 70° with strong dispersion. It exhibits weak to moderate pleochroism: orangish-yellow parallel to cleavage and greenish-yellow perpendicular to cleavage on (010). The measured Z ∧ c is 5–12°. The birefringence is strong to extreme; interference colors are very high-order tints...
FIGURES | View All (7)
Journal Article
Published: 01 September 2018
European Journal of Mineralogy (2018) 30 (5): 999–1006.
..., meitnerite is biaxial (–), with α = 1.568(2), β = 1.589(2), γ = 1.607(2) (white light); 2 V = 84(1)°. The dispersion is r > v , moderate, The optical orientation is X ∧ b = 26°, Y ∧ a = 15°, Z ∧ c = 53°. The pleochroism is X nearly colourless, Z pale green yellow, Y light green yellow; X < Z < Y...
FIGURES | View All (6)
Journal Article
Published: 01 September 2018
The Canadian Mineralogist (2018) 56 (5): 811–820.
...: perfect on {001} and good on {100}. The measured density is 2.85(2) g/cm 3 . Pararaisaite is biaxial (+) with α = 1.600(2), β = 1.616(2), γ = 1.713(3) (white light); 2 V = 47(1)°; slight r > v dispersion; orientation Z = b , X ≈ a , Y ≈ c ; and pleochroism X very pale purple, Y purple, Z blue green ( X...
FIGURES | View All (5)
Journal Article
Published: 01 July 2018
European Journal of Mineralogy (2018) 30 (4): 811–820.
... is ∼5. The calculated density is 3.613 g/cm 3 (for empirical formula). Optically, it is biaxial positive, with α = 1.674(2); β = 1.692(3) and γ = 1.730(3); 2 V γ is very large, ∼75° (est.), 2 V γ (calc.) = 70°. Pleochroism is moderate: X (pale) blue, Y pale blue and Z pale blue with faint greenish tint...
FIGURES
Journal Article
Published: 01 May 2018
European Journal of Mineralogy (2018) 30 (3): 537–544.
FIGURES | View All (6)
Journal Article
Published: 01 April 2018
Mineralogical Magazine (2018) 82 (2): 401–411.
...°. Dispersion is moderate, r < v . Pleochroism is X = very pale yellow green, Y = pale yellow green and Z = light yellow green; X < Y < Z . The optical orientation is X ≈ c , Y ≈ a and Z ≈ b* . The Raman spectrum exhibits bands attributable to both sulfate and uranyl groups. Electron probe...
FIGURES | View All (5)
Journal Article
Published: 01 February 2018
Mineralogical Magazine (2018) 82 (1): 199–209.
... density is 6.324 g cm –3 . In reflected light bytízite is grey with a yellowish hue, yellowish and brownish. Bireflectance and pleochroism are weak. Anisotropy is strong with grey to brownish rotation tints. Internal reflections were not observed. The empirical formula, based on electron-microprobe...
FIGURES | View All (5)