Hydroxyl Stretching Frequencies in the Infrared Spectra of Anthophyllites and Gedrites

Burns, Roger G.; Law, Anthony D.

doi:10.1038/226073a0

Cited by 14 publications

(3 citation statements)

References 4 publications

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“…The full width at half maximum heights are roughly equal for all components, 10.1-10.4 cm −1 . Based on the OH-stretching IR bands in orthorhombic Pnma amphiboles such as holmquistite and the anthophyllite-gedrite series (Ishida and Hawthorne, 2003;Kloprogge et al, 2001;Law, , 1982Law and Whittaker, 1981;Burns and Law, 1970;Wilkins et al, 1970), the four main bands, labeled A, B, C and D, are assigned to local configurations M1M1M3-O3H-A, where A = ( , Na) and M1M1M3 = MgMgMg, MgMgFe (including MgFeMg and FeMgMg), MgFeFe (including FeMgFe and FeFeMg) 3.223(3) * <λ> and σ θ 2 are bond-length distortion and angle variance, respectively (Robinson et al, 1971).…”

Section: Hydrogen Bondingmentioning

confidence: 99%

Ferro-ferri-holmquistite, □Li₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂, Fe²⁺Fe³⁺ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

Nagashima

Imaoka²,

Kano³

et al. 2022

Eur. J. Mineral.

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Abstract. Ferro-ferri-holmquistite (IMA2022-020), ideal formula □Li2(Fe32+Fe23+)Si8O22(OH)2, was found in albitized granite from the Iwagi islet, Ehime, Japan. Ferro-ferri-holmquistite is a CFe2+Fe3+ analogue of holmquistite and belongs to the lithium-subgroup amphiboles. It commonly occurs as acicular aggregate and/or isolated crystals in quartz, albite and K-feldspar and is blue with a bluish-grey streak and a vitreous luster. It has a Mohs hardness of 5 1/2. Its cleavage is perfect on {210}. Measured and calculated densities are Dmeas.=3.2 g cm−3 and Dcalc.=3.317 g cm−3, respectively. Ferro-ferri-holmquistite is optically biaxial (-), with α=1.685, β=1.713 and γ=1.727, and is pleochroic, with X= pale blue ∼ pale yellowish blue, Y= deep blue ∼ brownish blue and Z= deep blue ∼ deep bluish violet; X>Z>Y. The magnetic susceptibility is similar to the associated biotite. Ferro-ferri-holmquistite is insoluble in HCl, HNO3 and H2SO4. The empirical formula calculated on the basis of Σ(C+T) = 13 on the results obtained by electron microprobe analyzer (EPMA), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is A(K0.01Na0.06)Σ0.07B(Li1.95Na0.04Ca0.01)Σ2.00C(Fe2.822+Fe1.393+Al0.51Mg0.22Mn0.052+Ti0.01)Σ5.00T(Si7.98Al0.02)Σ8.00O22(OH)1.94F0.06. Structure refinement converged to R1= 4.22 %. The space group is orthorhombic Pnma, and the unit-cell parameters are a= 18.5437(2) Å, b= 17.9222(1) Å, c= 5.3123(1) Å and V= 1765.51(1) Å3. Based on the refined site occupancies, the structural formula can be written as ANa0.062M4(Li1.952Na0.048)Σ2.000M1(Fe1.7702+Mg0.230)Σ2.000M2(Fe1.4463+Fe0.1022+Al0.452)Σ2.000M3(Fe0.8912+Mg0.109)Σ1.000TSi8O22(OH)2 (Z= 4). Three OH-stretching IR bands, centered at 3614, 3631 and 3644 cm−1, are assigned to the local configuration M1M1M3= FeFeFe, MgFeFe (including FeMgFe and FeFeMg) and MgMgFe (including MgFeMg and FeMgMg), respectively, based on the IR studies of the orthorhombic Pnma amphiboles.

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Section: Hydrogen Bondingmentioning

confidence: 99%

Ferro-ferri-holmquistite, □Li₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂, Fe²⁺Fe³⁺ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

Nagashima

Imaoka²,

Kano³

et al. 2022

Eur. J. Mineral.

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“…The non-destructive, non-invasive properties of infrared (IR) and, being part of the electromagnetic spectrum, its ability to travel in a vacuum, have meant it has found a use in a wide range of disciplines including conservation and heritage, 56 astronomy, 57 mineralogy 58 and engineering. 59,60 IRT was first used for medical purposes in the 1950s for the identification of breast malignancy.…”

Section: Pet/ctmentioning

confidence: 99%

The use of infrared thermography in the measurement and characterization of brown adipose tissue activation

et al. 2018

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“…Many works on the hydroxyl group of amphiboles have been carried out using IR or Raman spectroscopy [1,[12][13][14][15][16][17]. Previous studies on tremolite-actinolite or nephrite show that the OH-stretching vibration bands, depending on the electronegativity of the bonded Fe and Mg cations in two M 1 and one M 3 sites, present one [4,10,11,18].…”

Section: Oh Bands: Oxidation-dehydrogenationmentioning

confidence: 99%

A Raman spectroscopic study of heat-treated nephrite

Chen¹

2008

Phase Transitions

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This study concerns the detection of heated nephrite jade, as some issues remain debatable: was heat-treatment used to facilitate jade carving or to modify jade's colour in ancient China? Has jade been burnt during funeral ceremony? Have forgeries been heat-treated to give the appearance of naturally weathered and altered jades? The understanding of the effect of heat on nephrite can provide useful information for answering these questions. Nephrite breaks down when heated above 840 C, and the phase transition is easily identified. However, detecting nephrite heated below 800 C was a challenging task as no principle crystal phase transition occurs. In this work, Raman spectroscopy is employed to study heated nephrite in a nondestructive way. For the first time, the subtle changes of molecular structure of nephrite heated below 840 C are reported in detail. The results show that the oxidation-dehydrogenation phenomenon is the key to understand the modification in heated nephrite.

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Hydroxyl Stretching Frequencies in the Infrared Spectra of Anthophyllites and Gedrites

Cited by 14 publications

References 4 publications

Ferro-ferri-holmquistite, □Li₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂, Fe²⁺Fe³⁺ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

Ferro-ferri-holmquistite, □Li₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂, Fe²⁺Fe³⁺ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

The use of infrared thermography in the measurement and characterization of brown adipose tissue activation

A Raman spectroscopic study of heat-treated nephrite

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Hydroxyl Stretching Frequencies in the Infrared Spectra of Anthophyllites and Gedrites

Cited by 14 publications

References 4 publications

Ferro-ferri-holmquistite, □Li2(Fe2+3Fe3+2)Si8O22(OH)2, Fe2+Fe3+ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

Ferro-ferri-holmquistite, □Li2(Fe2+3Fe3+2)Si8O22(OH)2, Fe2+Fe3+ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

The use of infrared thermography in the measurement and characterization of brown adipose tissue activation

A Raman spectroscopic study of heat-treated nephrite

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Ferro-ferri-holmquistite, □Li₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂, Fe²⁺Fe³⁺ analogue of holmquistite, from the Iwagi islet, Ehime, Japan

Ferro-ferri-holmquistite, □Li₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂, Fe²⁺Fe³⁺ analogue of holmquistite, from the Iwagi islet, Ehime, Japan