Ferro-holmquistite (original) (raw)

A valid IMA mineral species

Formula:

◻{Li2}{Fe2+3Al2}(Si8O22)(OH)2

The holmquistite group comprises orthorhombic amphiboles in the lithium amphibole subgroup.

Holmquistite is defined with Fe2+Mg and Al>Fe3+ in the C position.
The type material is Mg-rich.

Colour:

Black, dark-violet, light sky-blue.

Specific Gravity:

3.145 (Calculated)

Crystal System:

Orthorhombic

Name:

For its relationship to holmquistite.

Ferro-holmquistite forms a series with holmquistite. Like holmquistite, ferro-holmquistite is almost exclusively formed in the reaction zone between Li-pegmatites and their host rock, predominantly as a metasomatic alteration product of pre-existing amphiboles. Quéméneur and Lagache(1994) show a significant variation of Fe content in holmquistite from different localities and they suggest that the holmquistite minerals retain their Fe/Mg ratio from the original amphibole.

Ferro-holmquistite is under-reported in the literature, as both ferro-holmquistite and holmquistite are often referred to as holmquistite.

Unique IdentifiersHide

This section is currently hidden. Click the show button to view.

Long-form identifier:

mindat:1:1:8957:5

56c3a52e-3cc9-4c57-8689-f9322c4283ab

IMA Classification of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

IMA status notes:

Redefined by the IMA

IMA Formula:

◻Li2(Fe2+3Al2)Si8O22(OH)2

Approval history:

Redefined IMA 2012 s.p.

Classification of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

9.DD.05

9 : SILICATES (Germanates)
D : Inosilicates
D : Inosilicates with 2-periodic double chains, Si4O11; Orthoamphiboles

Mineral SymbolsHide

This section is currently hidden. Click the show button to view.

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Physical Properties of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

Colour:

Black, dark-violet, light sky-blue.

Streak:

Light bluish-violet. White with a sky-blue tinge (?)

Density:

3.145 g/cm3 (Calculated)

Optical Data of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

RI values:

_n_α = 1.628 _n_β = 1.646 _n_γ = 1.651

δ = 0.023

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.

Optical Extinction:

c = X, with the optic axial plane coinciding with (010).

Comments:

α = colorless, β = pale violet-blue, γ = blue to deep violet.

Chemistry of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

Mindat Formula:

◻{Li2}{Fe2+3Al2}(Si8O22)(OH)2

The holmquistite group comprises orthorhombic amphiboles in the lithium amphibole subgroup.

Holmquistite is defined with Fe2+Mg and Al>Fe3+ in the C position.
The type material is Mg-rich.

Crystallography of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

Crystal System:

Orthorhombic

Class (H-M):

m m m _(_2/_m_2/_m_2/m ) - Dipyramidal

Cell Parameters:

a = 18.287 Å, b = 17.68 Å, c = 5.278 Å

Ratio:

a:b:c = 1.034 : 1 : 0.299

Morphology:

Prismatic crystals.

Crystal StructureHide

This section is currently hidden. Click the show button to view.

Load
Unit Cell |Unit Cell Packed
2x2x2 |3x3x3 |4x4x4

Show
Big Balls |Small Balls |Just Balls |Spacefill
Polyhedra Off |Si Polyhedra |All Polyhedra
Remove metal-metal sticks

Display Options
Black Background |White Background
Perspective On |Perspective Off
2D |Stereo |Red-Blue |Red-Cyan

View
CIF File Best |x |y |z |a |b |c

Rotation
Stop |Start

Labels
Console Off |On |Grey |Yellow

ID	Species	Reference	Link	Year	Locality	Pressure (GPa)	Temp (K)
0003812	Ferro-holmquistite	Camara F, Oberti R (2005) The crystal-chemistry of holmquistites: Ferroholmquistite from Greenbushes (Western Australia) and hints for compositional constraints in B-Li amphiboles American Mineralogist 90 1167-1176		2005	0	293

CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

This section is currently hidden. Click the show button to view.

Powder Diffraction Data:

Comments:

Greenbushes Mine, Western Australia, Australia. The data are from Camara and Oberti (2005).

Geological EnvironmentHide

This section is currently hidden. Click the show button to view.

Type Occurrence of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

General Appearance of Type Material:

Elongated black to bluish-violet prismatic crystals, typically in the range 0.2–0.5 mm.

Place of Conservation of Type Material:

Museum of the Dipartimento di Scienze della Terra, Universita di Pavia #2004-01

Empirical Formula of Type Material:

A(K0.01Na0.01)B(Li1.88Mg0.08Na0.03Fe2+ 0.01) C(Al1.89Fe2+ 1.70Mg1.39Mn2+ 0.02) TSi8.00O22(OH1.97F0.03)

Chemical Analysis of Type Material:

Geological Setting of Type Material:

Lithium-rich granite pegmatite.

Associated Minerals at Type Locality:

Synonyms of Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

Other Language Names for Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

Relationship of Ferro-holmquistite to other SpeciesHide

This section is currently hidden. Click the show button to view.

Other Members of this group:

Related Minerals - Strunz-mindat GroupingHide

This section is currently hidden. Click the show button to view.

Other InformationHide

This section is currently hidden. Click the show button to view.

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-holmquistiteHide

This section is currently hidden. Click the show button to view.

References for Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

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

Localities for Ferro-holmquistiteHide

This section is currently hidden. Click the show button to view.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

This section is currently hidden. Click the show button to view.

- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.