Anthophyllite
A valid IMA mineral species - grandfathered
This page kindly sponsored by Robert M. Hazen
About Anthophyllite
Formula:
◻{Mg2}{Mg5}(Si8O22)(OH)2
The anthophyllite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup. The minerals in this root name group may have either Pnma or Pnmn (proto- prefixed name) space-group symmetry. The anthophyllite group's composition is defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)<1 apfu.
Anthophyllite has a standard Pnma space-group symmetry and is defined with Mg as the dominant element both in the B and C positions.
Anthophyllite has a standard Pnma space-group symmetry and is defined with Mg as the dominant element both in the B and C positions.
Colour:
White, greenish grey, green, clove brown, or brownish green
Lustre:
Vitreous, Pearly
Hardness:
5½ - 6
Specific Gravity:
2.85 - 3.57
Crystal System:
Orthorhombic
Member of:
Name:
First described by Schumacher (1801) as a new mineral from the Kongsberg area, Norway. He named it "anthophyllum" from the Latin meaning "clove" (itself derived from the Greek άνθος for "flower" and φύλλον for "leaf" ), in allusion to its common clove-brown colour.
Type Locality:
Dimorph of:
Forms a series with ferro-anthophyllite.
May be easily confused with proto-anthophyllite.
Visit gemdat.org for gemological information about Anthophyllite.
May be easily confused with proto-anthophyllite.
Visit gemdat.org for gemological information about Anthophyllite.Unique Identifiers
Mindat ID:
254
Long-form identifier:
mindat:1:1:254:5
GUID
(UUID V4):
(UUID V4):
d6076d55-9ac4-4775-8aee-5da1a2adde3b
IMA Classification of Anthophyllite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
◻Mg2Mg5Si8O22(OH)2
Classification of Anthophyllite
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
66.1.2.1
66 : INOSILICATES Double-Width,Unbranched Chains,(W=2)
1 : Amphiboles - Mg-Fe-Mn-Li subgroup
66 : INOSILICATES Double-Width,Unbranched Chains,(W=2)
1 : Amphiboles - Mg-Fe-Mn-Li subgroup
14.21.5
14 : Silicates not Containing Aluminum
21 : Silicates of Fe and Mg
14 : Silicates not Containing Aluminum
21 : Silicates of Fe and Mg
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference |
|---|---|---|
| Ath | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Ath | Kretz (1983) | Kretz, R. (1983) Symbols of rock-forming minerals. American Mineralogist, 68, 277–279. |
| Ath | Siivolam & Schmid (2007) | Siivolam, J. and Schmid, R. (2007) Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Web-version 01.02.07. IUGS Commission on the Systematics in Petrology. download |
| Ath | Whitney & Evans (2010) | Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187 doi:10.2138/am.2010.3371 |
| Ath | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
| Ath | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Anthophyllite
Vitreous, Pearly
Transparency:
Transparent, Translucent
Colour:
White, greenish grey, green, clove brown, or brownish green
Streak:
White to greyish-white.
Hardness:
5½ - 6 on Mohs scale
Cleavage:
Perfect
Perfect on {210}, imperfect on {010}, {100}
Perfect on {210}, imperfect on {010}, {100}
Fracture:
Conchoidal
Density:
2.85 - 3.57 g/cm3 (Measured) 3.67 g/cm3 (Calculated)
Optical Data of Anthophyllite
Type:
Biaxial (+)
RI values:
nα = 1.598 - 1.674 nβ = 1.605 - 1.685 nγ = 1.615 - 1.697
2V:
Measured: 57° to 90°, Calculated: 82° to 90°
Max Birefringence:
δ = 0.017 - 0.023
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
r > v or r < v
Chemistry of Anthophyllite
Mindat Formula:
◻{Mg2}{Mg5}(Si8O22)(OH)2
The anthophyllite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup. The minerals in this root name group may have either Pnma or Pnmn (proto- prefixed name) space-group symmetry. The anthophyllite group's composition is defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)<1 apfu.
Anthophyllite has a standard Pnma space-group symmetry and is defined with Mg as the dominant element both in the B and C positions.
The anthophyllite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup. The minerals in this root name group may have either Pnma or Pnmn (proto- prefixed name) space-group symmetry. The anthophyllite group's composition is defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)<1 apfu.
Anthophyllite has a standard Pnma space-group symmetry and is defined with Mg as the dominant element both in the B and C positions.
Elements listed:
Common Impurities:
Ti,Al,Mn,Ca,Na
Chemical Analysis
Oxide wt%:
| 1 | |
|---|---|
| P2O5 | 0.02 % |
| SiO2 | 53.35 % |
| TiO2 | 0.07 % |
| Al2O3 | 11.69 % |
| V2O3 | 0.01 % |
| Cr2O3 | 0.03 % |
| Sc2O3 | 0.01 % |
| Fe2O3* | 0.86 % |
| FeO* | 1.49 % |
| MnO | 0.46 % |
| CoO | 0.01 % |
| NiO | 0.03 % |
| ZnO | 0.02 % |
| MgO | 28.73 % |
| CaO | 0.62 % |
| SrO | 0.02 % |
| Na2O | 0.15 % |
| K2O | 0.01 % |
| F | 0.05 % |
| H2O (by stoichiometry) | 2.23 % |
| -O=F | -0.02 % |
| Total: | 99.84 % |
Empirical formulas:
| Sample ID | Empirical Formula |
|---|---|
| 1 | ◻1.00(Mg1.65Fe2+0.17Ca0.09Mn2+0.05Na0.04)(Mg4.01Al0.88Fe3+0.09Ti0.01)[Si7.06Al0.94O22]([OH]1.97F0.02O0.01) |
Sample references:
| ID | Locality | Reference | Notes |
|---|---|---|---|
| 1 | Mautia Hill, Kongwa, Kongwa District, Dodoma Region, Tanzania | Frank K. Mazdab collectionsample FKM-307; https://www.rockptx.com/fkm-301-to-fkm-325/#FKM-307 | sample is composed of a single anthophyllite crystal hosting "green" yoderite (almost colorless in thin section) along with minor talc and scattered hematite, rutile and zircon. Anthophyllite microprobe data are normalized to 15eK (no Na in A-site). *Fe measured as Fe2+; Fe3+ and H2O calculated by stoichiometry and site filling. Composition is nearly mid-way along the anthophyllite-gedrite join, according to Hawthorne et al., 2012. Note that the reported Mg-Fe distribution between M4 and (M1+M2+M3) here is not structurally verified, but is just a simplification based on filling the VI-coordinated smaller sites with smaller Mg first, before using larger Fe2+. |
Crystallography of Anthophyllite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pnma
Cell Parameters:
a = 18.544(2) Å, b = 18.026(2) Å, c = 5.282(1) Å
Ratio:
a:b:c = 1.029 : 1 : 0.293
Unit Cell V:
1,765.64 ų (Calculated from Unit Cell)
Z:
4
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0017657 | Anthophyllite | Warren B, Modell D (1930) The structure of Anthophyllite H2 Mg7 (Si O3)8 _cod_database_code 1010935 Zeitschrift fur Kristallographie 75 161-179 | 1930 | 0 | 293 | ||
| 0010994 | Anthophyllite | Walitzi E M, Walter F, Ettinger K (1989) Verfeinerung der kristallstruktur von anthophyllit vom Ochsenkogel/Gleinalpe, Osterreich Zeitschrift fur Kristallographie 188 237-244 |  | 1989 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.9 Å | (30) |
| 8.26 Å | (55) |
| 3.65 Å | (35) |
| 3.24 Å | (60) |
| 3.05 Å | (100) |
| 2.84 Å | (40) |
| 2.54 Å | (40) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 2: Planetesimal differentiation and alteration | 4.566-4.550 |
| 6 : Secondary asteroid phases | 4.566-4.560 |
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 9 : Lava/xenolith minerals (hornfels, sanidinite facies) | |
| Near-surface Processes | |
| 26 : Hadean detrital minerals | |
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 40 : Regional metamorphism (greenschist, amphibolite, granulite facies) |
Geological Setting:
Generally occurs in medium- or high-grade metamorphic rocks; in amphibolites, gneisses, metaquartzites, iron formations, granulites, and schists derived from argillaceous sediments, ultramafic, or mafic igneous rocks; also as a retrograde reaction product.
Type Occurrence of Anthophyllite
Reference:
Schumacher, C.F. (1801) Versuch eines Verzeichnisses der in den Dänisch-Nordischen Staaten sich findenden einfachen Mineralien. Kopenhagen, 96.
Synonyms of Anthophyllite
Other Language Names for Anthophyllite
Varieties of Anthophyllite
| Kupfferite (of Koksarov) | A Cr-bearing variety of anthophyllite. |
Relationship of Anthophyllite to other Species
Member of:
Other Members of this group:
| Ferro-anthophyllite | ◻{Fe2+2}{Fe2+5}(Si8O22)(OH)2 | Orth. mmm (2/m 2/m 2/m) : Pnma |
| Proto-anthophyllite | ◻{Mg2}{Mg5}(Si8O22)(OH)2 | Orth. mmm (2/m 2/m 2/m) : Pnnm |
| Proto-ferro-anthophyllite | ◻{Fe2+2}{Fe2+5}(Si8O22)(OH)2 | Orth. mmm (2/m 2/m 2/m) |
| Sodic-ferro-anthophyllite | {Na}{Fe2+2}{Fe2+5}(AlSi7O22)(OH)2 | Orth. |
Forms a series with:
Common Associates
Associated Minerals Based on Photo Data:
| 34 photos of Anthophyllite associated with Talc | Mg3Si4O10(OH)2 |
| 28 photos of Anthophyllite associated with Phlogopite | KMg3(AlSi3O10)(OH)2 |
| 25 photos of Anthophyllite associated with Tremolite | ◻Ca2Mg5(Si8O22)(OH)2 |
| 13 photos of Anthophyllite associated with Chlorite Group | |
| 12 photos of Anthophyllite associated with Clino-suenoite | ◻{Mn2+2}{Mg5}(Si8O22)(OH)2 |
| 11 photos of Anthophyllite associated with Quartz | SiO2 |
| 11 photos of Anthophyllite associated with Chesterite | (Mg,Fe)17Si20O54(OH)6 |
| 11 photos of Anthophyllite associated with Jimthompsonite | (Mg,Fe)5Si6O16(OH)2 |
| 11 photos of Anthophyllite associated with Clinojimthompsonite | (Mg,Fe)5Si6O16(OH)2 |
| 11 photos of Anthophyllite associated with Magnetite | Fe2+Fe3+2O4 |
Related Minerals - Strunz-mindat Grouping
| 9.DD.05 | Ferro-anthophyllite | ◻{Fe2+2}{Fe2+5}(Si8O22)(OH)2 |
| 9.DD.05 | Ferro-gedrite | ◻{Fe2+2}{Fe2+3Al2}(Al2Si6O22)(OH)2 |
| 9.DD.05 | Gedrite | ◻{Mg2}{Mg3Al2}(Al2Si6O22)(OH)2 |
| 9.DD.05 | Holmquistite | ◻{Li2}{Mg3Al2}(Si8O22)(OH)2 |
| 9.DD.05 | Proto-ferro-anthophyllite | ◻{Fe2+2}{Fe2+5}(Si8O22)(OH)2 |
| 9.DD.05 | Proto-ferro-suenoite | ◻{Mn2+2}{Fe2+5}(Si8O22)(OH)2 |
| 9.DD.05 | Sodic-anthophyllite | {Na}{Mg2}{Mg5}(AlSi7O22)(OH)2 |
| 9.DD.05 | Sodic-ferro-anthophyllite | {Na}{Fe2+2}{Fe2+5}(AlSi7O22)(OH)2 |
| 9.DD.05 | Ferro-holmquistite | ◻{Li2}{Fe2+3Al2}(Si8O22)(OH)2 |
| 9.DD.05 | Proto-anthophyllite | ◻{Mg2}{Mg5}(Si8O22)(OH)2 |
| 9.DD.05 | Lavinskyite | K(LiCu)Cu6(Si4O11)2(OH)4 |
| 9.DD.05 | Papikeite | NaMg2(Mg3Al2}(Al3Si5O22)(OH)2 |
| 9.DD.05 | Ferri-holmquistite | ◻{Li2}{Mg3Fe3+2}(Si8O22)(OH)2 |
| 9.DD.05 | Ferro-ferri-holmquistite | ◻{Li2}{Fe2+3Fe3+2}(Si8O22)(OH)2 |
| 9.DD.05 | Suenoite | ◻Mn2Mg5Si8O22(OH)2 |
| 9.DD.05 | Ferro-papikeite | NaFe2+2(Fe2+3Al2)(Si5Al3O22)(OH)2 |
Other Information
Health Risks:
Asbestiform habits of the mineral should be handled with care.
This mineral is known to be a respirable carcinogen, and is a common form of asbestos. Exposure to very dusty air or long-term exposure to low level airborne dusts containing fine fibres of the mineral has been found to cause a high risk of serious lung disease including mesothelioma and lung cancer. Care should be taken working with samples that contain fibrous forms of this mineral, to avoid creating or inhaling dusts. Non-fibrous forms, such as in many amphibolites, are safer to handle, but can still produce potentially carcinogenic respirable fibre when crushed. Appropriate dust masks should be worn if working in areas which have dusts likely to be rich in this mineral. Storage and careful handling of specimens has little or no risk.
This mineral is known to be a respirable carcinogen, and is a common form of asbestos. Exposure to very dusty air or long-term exposure to low level airborne dusts containing fine fibres of the mineral has been found to cause a high risk of serious lung disease including mesothelioma and lung cancer. Care should be taken working with samples that contain fibrous forms of this mineral, to avoid creating or inhaling dusts. Non-fibrous forms, such as in many amphibolites, are safer to handle, but can still produce potentially carcinogenic respirable fibre when crushed. Appropriate dust masks should be worn if working in areas which have dusts likely to be rich in this mineral. Storage and careful handling of specimens has little or no risk.
Internet Links for Anthophyllite
mindat.org URL:
https://www.mindat.org/min-254.html
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References for Anthophyllite
Reference List:
Schumacher, Christian Friedrich (1801) Versuch eines Verzeichnisses der in den Dänisch- Nordischen Staaten sich findenden einfachen Mineralien mit Tabellen der einfachen Fossilien nach ihren vorwaltenden Bestandtheilen. F. Brummer, Copenhagen. p.96 - first description of the mineral
Veblen, David R (1980) Anthophyllite asbestos: microstructures, intergrown sheet silicates, and mechanisms of fiber formation. American Mineralogist, 65 (11-12) 1075-1086
Walter, F., Walitzi, Ε. M., Mereiter, K. (1989) Verfeinerung der Kristallstruktur von Holmquistit vom Brandrücken/Weinebene, Koralpe, Österreich. Zeitschrift für Kristallographie - Crystalline Materials, 188 (14) 95 doi:10.1524/zkri.1989.188.14.95
Ishida, K., Hawthorne, F. C. (2003) Fine structure in the infrared OH-stretching bands of holmquistite and anthophyllite. Physics and Chemistry of Minerals, 30 (6) 330-336 doi:10.1007/s00269-003-0311-9
Hawthorne, F. C., Oberti, R. (2006) On the classification of amphiboles. The Canadian Mineralogist, 44 (1) 1-21 doi:10.2113/gscanmin.44.1.1
Localities for Anthophyllite
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.
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Heřmanov, Žďár nad Sázavou District, Vysočina Region, Czech Republic