Ferro-ferri-holmquistite
A valid IMA mineral species
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About Ferro-ferri-holmquistite
Formula:
◻Li2(Fe2+3Fe3+2)(Si8O22)(OH)2
The holmquistite group are orthorhombic amphiboles in the lithium amphibole subgroup.
Ferro-ferri-holmquistite is defined with Fe2+>Mg and Fe3+>Al in the C position
Ferro-ferri-holmquistite is defined with Fe2+>Mg and Fe3+>Al in the C position
Colour:
Blue
Lustre:
Vitreous
Hardness:
5½
Specific Gravity:
3.32
Crystal System:
Orthorhombic
Member of:
Name:
Named according to the amphibole nomenclature. The CFe2+Fe3+ analogue of holmquistite.
Type Locality:
Dimorph of:
Unique Identifiers
Mindat ID:
43516
Long-form identifier:
mindat:1:1:43516:9
IMA Classification of Ferro-ferri-holmquistite
Classification of Ferro-ferri-holmquistite
9.DD.05
9 : SILICATES (Germanates)
D : Inosilicates
D : Inosilicates with 2-periodic double chains, Si4O11; Orthoamphiboles
9 : SILICATES (Germanates)
D : Inosilicates
D : Inosilicates with 2-periodic double chains, Si4O11; Orthoamphiboles
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ffhlm | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Ferro-ferri-holmquistite
Vitreous
Colour:
Blue
Streak:
Bluish-grey
Hardness:
5½ on Mohs scale
Cleavage:
Perfect
On {210}.
On {210}.
Density:
3.32 g/cm3 (Measured) 3.317 g/cm3 (Calculated)
Comment:
Measured using floatation on heavy liquids. Calculated using the empirical formula.
Optical Data of Ferro-ferri-holmquistite
Type:
Biaxial (-)
RI values:
nα = 1.685 nβ = 1.713 nγ = 1.727
2V:
Measured: 45° to 75°, Calculated: 70°
Max. Birefringence:
δ = 0.042
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Pleochroism:
Visible
Comments:
X = pale blue / pale yellowish blue; Y = deep blue / brownish blue; Z = deep blue / deep bluish violet
Comments:
Absorption: X > Z > Y.
Chemistry of Ferro-ferri-holmquistite
Mindat Formula:
◻Li2(Fe2+3Fe3+2)(Si8O22)(OH)2
The holmquistite group are orthorhombic amphiboles in the lithium amphibole subgroup.
Ferro-ferri-holmquistite is defined with Fe2+>Mg and Fe3+>Al in the C position
The holmquistite group are orthorhombic amphiboles in the lithium amphibole subgroup.
Ferro-ferri-holmquistite is defined with Fe2+>Mg and Fe3+>Al in the C position
Element Weights:
Crystallography of Ferro-ferri-holmquistite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pmma
Setting:
Pmma
Cell Parameters:
a = 18.5437(2) Å, b = 17.9222(1) Å, c = 5.3123(1) Å
Ratio:
a:b:c = 1.035 : 1 : 0.296
Unit Cell V:
1,765.51 ų (Calculated from Unit Cell)
Morphology:
Acicular aggregates and isolated crystals.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.256 Å | (100) |
| 4.487 Å | (15) |
| 3.346 Å | (11) |
| 3.227 Å | (6) |
| 3.043 Å | (88) |
| 2.745 Å | (15) |
| 2.592 Å | (3) |
| 2.496 Å | (3) |
Type Occurrence of Ferro-ferri-holmquistite
General Appearance of Type Material:
Acicular aggregates and/or isolated crystals.
Place of Conservation of Type Material:
Mineralogical collections of the National Museum of Nature and Science, Amakubo 4-1-1, Tsukuba, Ibaraki 305-0005, Japan, specimen number NSM-M49617.
Empirical Formula of Type Material:
A(K0.01Na0.06)B0.07(Li1.95Na0.04Ca0.01)2.00C(Fe2+2.82Fe3+1.39Al0.51Mg0.22Mn2+0.05Ti0.01)T?5.00(Si7.98Al0.02)?8.00O22(OH)1.94F0.06
Chemical Analysis of Type Material:
| SiO2 | 53.63 % |
|---|---|
| TiO2 | 0.1 % |
| Al2O3 | 3.04 % |
| Fe2O3 | 12.39 % |
| FeO | 22.63 % |
| MnO | 0.37 % |
| MgO | 0.99 % |
| CaO | 0.04 % |
| Na2O | 0.35 % |
| K2O | 0.03 % |
| Li2O | 3.26 % |
| F | 0.16 % |
| H2O | 1.95 % |
| O=F | 0.07 % |
| Total: | 99.01 % |
Geological Setting of Type Material:
Albitized granite.
Associated Minerals at Type Locality:
Other Language Names for Ferro-ferri-holmquistite
Relationship of Ferro-ferri-holmquistite to other Species
Member of:
Other Members of Holmquistite Root Name Group:
| Ferro-holmquistite | ◻Li2(Fe2+3Al2)(Si8O22)(OH)2 | Orth. mmm(2/m2/m2/m) : Pnma |
| Holmquistite | ◻Li2(Mg3Al2)(Si8O22)(OH)2 | Orth. mmm(2/m2/m2/m) : Pnma |
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 9.DD.05 | Suenoite | ◻Mn2+2Mg5Si8O22(OH)2 |
| 9.DD.05 | Proto-ferro-anthophyllite | ◻Fe2+2Fe2+5(Si8O22)(OH)2 |
| 9.DD.05 | Proto-ferro-suenoite | ◻Mn2+2(Fe2+5)(Si8O22)(OH)2 |
| 9.DD.05 | Papikeite | NaMg2(Mg3Al2}(Al3Si5O22)(OH)2 |
| 9.DD.05 | Gedrite | ◻Mg2(Mg3Al2)(Al2Si6O22)(OH)2 |
| 9.DD.05 | Holmquistite | ◻Li2(Mg3Al2)(Si8O22)(OH)2 |
| 9.DD.05 | 'Sodic-anthophyllite' | {Na}{Mg2}{Mg5}(AlSi7O22)(OH)2 |
| 9.DD.05 | 'Sodic-ferro-anthophyllite' | NaFe2+2Fe2+5(AlSi7O22)(OH)2 |
| 9.DD.05 | Ferro-papikeite | NaFe2+2(Fe2+3Al2)(Si5Al3O22)(OH)2 |
| 9.DD.05 | Ferro-anthophyllite | ◻Fe2+2Fe2+5(Si8O22)(OH)2 |
| 9.DD.05 | Proto-anthophyllite | ◻Mg2Mg5(Si8O22)(OH)2 |
| 9.DD.05 | Ferro-gedrite | ◻Fe2+2(Fe2+3Al2)(Al2Si6O22)(OH)2 |
| 9.DD.05 | 'Ferri-holmquistite' | ◻{Li2}{Mg3Fe3+2}(Si8O22)(OH)2 |
| 9.DD.05 | Ferro-holmquistite | ◻Li2(Fe2+3Al2)(Si8O22)(OH)2 |
| 9.DD.05 | Anthophyllite | ◻Mg2Mg5(Si8O22)(OH)2 |
Other Information
IR Spectrum:
OH stretching vibrations [cm-1]: 3614 (due to the local configuration M1M1M3 = FeFeFe) 3631 (M1M1M3 = MgFeFe, including FeMgFe and FeFeMg), and 3644 (M1M1M3 = MgMgFe, including MgFeMg and FeMgMg.
Notes:
Magnetic susceptibility is similar to that of the associated biotite and slightly higher than aegirine-augite.
Insoluble in HCl, HNO3 and H2SO4.
Insoluble in HCl, HNO3 and H2SO4.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Ferro-ferri-holmquistite
mindat.org URL:
https://www.mindat.org/min-43516.html
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Please feel free to link to this page.
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References for Ferro-ferri-holmquistite
Reference List:
Hawthorne, F. C., Oberti, R., Harlow, G. E., Maresch, W. V., Martin, R. F., Schumacher, J. C., Welch, M. D. (2012) Nomenclature of the amphibole supergroup. American Mineralogist, 97 (11) 2031-2048 doi:10.2138/am.2012.4276
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 68. European Journal of Mineralogy, 34 (5) 385-391 doi:10.5194/ejm-34-385-2022
Nagashima, Mariko, Imaoka, Teruyoshi, Kano, Takashi, Kimura, Jun-ichi, Chang, Qing, Matsumoto, Takashi (2022) Ferro-ferri-holmquistite, □Li2(Fe2+3Fe3+2)Si8O22(OH)2, Fe2+Fe3+ analogue of holmquistite, from the Iwagi islet, Ehime, Japan. European Journal of Mineralogy, 34 (5) 425-438 doi:10.5194/ejm-34-425-2022
Localities for Ferro-ferri-holmquistite
Showing 2 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Japan (TL) | |
| Miyawaki et al. (2022) |
| Imaoka et al. (2024) |
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Iwagi Island, Ochi District, Ehime Prefecture, Japan