Astrophyllite
A valid IMA mineral species - grandfathered
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About Astrophyllite
Formula:
K2NaFe2+7Ti2Si8O26(OH)4F
Colour:
Bronze-yellow, golden yellow, brown to reddish brown
Lustre:
Greasy, Pearly, Sub-Metallic
Hardness:
3
Specific Gravity:
3.2 - 3.4
Crystal System:
Triclinic
Member of:
Name:
From the Greek άστρον ("astron") for "star" and φύλλον ("phyllon") for "leaf", in allusion to its habit of starburst-like sprays and micaceous cleavage. It was named by the German chemist, geologist and mineralogist Carl Johan August Theodor Scheerer (1813-1875) in 1854.
Type Locality:
Astrophyllite Group.
The mineral was first found in 1844 by the Norwegian mineralogist Paul Christian Weibye (1819-1865) and later described by him, in 1848, as a brown, micaceous mineral ("brauner Glimmer") from Låven (formerly Lamöskjär), Langesundsfjorden, Norway (Weibye 1848). Later Scheerer (1854) described it under the name astrophyllite. Brøgger (1890) described in detail the crystallographic and optical properties as well as its chemistry.
The mineral was first found in 1844 by the Norwegian mineralogist Paul Christian Weibye (1819-1865) and later described by him, in 1848, as a brown, micaceous mineral ("brauner Glimmer") from Låven (formerly Lamöskjär), Langesundsfjorden, Norway (Weibye 1848). Later Scheerer (1854) described it under the name astrophyllite. Brøgger (1890) described in detail the crystallographic and optical properties as well as its chemistry.
Visit gemdat.org for gemological information about Astrophyllite.
Unique Identifiers
Mindat ID:
405
Long-form identifier:
mindat:1:1:405:7
GUID
(UUID V4):
(UUID V4):
70af7f27-38a9-4aca-b397-8dae58ded0f4
IMA Classification of Astrophyllite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
K2NaFe2+7Ti2(Si4O12)2O2(OH)4F
Classification of Astrophyllite
9.DC.05
9 : SILICATES (Germanates)
D : Inosilicates
C : Inosilicates with branched 2-periodic single chains; Si2O6 + 2SiO3 Si4O12
9 : SILICATES (Germanates)
D : Inosilicates
C : Inosilicates with branched 2-periodic single chains; Si2O6 + 2SiO3 Si4O12
69.1.1.1
69 : INOSILICATES Chains with Side Branches or Loops
1 : Chains with Side Branches or Loops with (P=2, and N=4, 2 branches)
69 : INOSILICATES Chains with Side Branches or Loops
1 : Chains with Side Branches or Loops with (P=2, and N=4, 2 branches)
14.9.29
14 : Silicates not Containing Aluminum
9 : Silicates of Ti
14 : Silicates not Containing Aluminum
9 : Silicates of Ti
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 |
---|---|---|
Ast | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Ast | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Ast | 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 Astrophyllite
Greasy, Pearly, Sub-Metallic
Transparency:
Translucent, Opaque
Colour:
Bronze-yellow, golden yellow, brown to reddish brown
Streak:
Golden
Hardness:
3 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
Perfect on {001}
Poor on {100}
Perfect on {001}
Poor on {100}
Fracture:
Irregular/Uneven
Density:
3.2 - 3.4 g/cm3 (Measured)
Optical Data of Astrophyllite
Type:
Biaxial (+)
RI values:
nα = 1.680 nβ = 1.700 nγ = 1.730
2V:
Measured: 70° to 90°, Calculated: 80°
Max Birefringence:
δ = 0.050
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:
High
Dispersion:
none
Optical Extinction:
X ≃ c; Y ≃ b; Z ≃ a.
Pleochroism:
Strong
Comments:
X= deep red-orange
Y= orange-yellow
Z= lemon-yellow
Y= orange-yellow
Z= lemon-yellow
Chemistry of Astrophyllite
Mindat Formula:
K2NaFe2+7Ti2Si8O26(OH)4F
Common Impurities:
Nb,Ta,Zr,Al,Mg,Ca
Chemical Analysis
Oxide wt%:
1 | |
---|---|
Na2O | 2.68 % |
K2O | 5.21 % |
Rb2O | 1.05 % |
Cs2O | 1.35 % |
CaO | 1.00 % |
SrO | 0.10 % |
MgO | 1.11 % |
MnO | 13.99 % |
FeO | 18.45 % |
ZnO | 0.49 % |
Al2O3 | 1.01 % |
Ce2O3 | 0.31 % |
TiO2 | 9.20 % |
SnO3 | 0.23 % |
ZrO2 | 1.69 % |
Nb2O5 | 2.81 % |
SiO2 | 33.98 % |
F | 1.38 % |
H2O | 2.65 % |
O=F | -0.58 % |
Total: | 98.11 % |
Sample references:
Crystallography of Astrophyllite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 11.76 Å, b = 5.36 Å, c = 21.08 Å
α = 90°, β = 94°, γ = 90°
α = 90°, β = 94°, γ = 90°
Ratio:
a:b:c = 2.194 : 1 : 3.933
Unit Cell V:
1,325.51 ų (Calculated from Unit Cell)
Morphology:
Tabular, bladed, acicular.
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) |
---|---|---|---|---|---|---|---|
0005802 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | Seal Lake, Labrador, Canada | 0 | 293 | |
0005803 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | Langesundsfjord area, Oslo Rift Valley, Norway | 0 | 293 | |
0005805 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | Khibina massif, Kola Peninsula, Russia | 0 | 293 | |
0005806 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | Khibina massif, Kola Peninsula, Russia | 0 | 293 | |
0005809 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | granitic pegmatite at Mount Rosa, Pikes Peak, Colorado, USA | 0 | 293 | |
0005818 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | aplite/pegmatite at Mont Saint-Hilaire, Quebec, Canada | 0 | 293 | |
0005819 | Astrophyllite | Piilonen P C, McDonald A M, Lalonde A E (2003) Insights into astrophyllite-group minerals II: Crystal chemistry The Canadian Mineralogist 41 27-54 | 2003 | nepheline syenite pegmatite at Mont Saint-Hilaire, Quebec, Canada | 0 | 293 | |
0007257 | Astrophyllite | Sokolova E, Camara F (2008) Re-investigation of the crystal structure of magnesium astrophyllite European Journal of Mineralogy 20 253-260 | 2008 | Mt. Yukspor, Khibina alkaline massif, Kola Peninsula, Russia | 0 | 293 | |
0009310 | Astrophyllite | Woodrow P J (1967) The crystal structure of astrophyllite Acta Crystallographica 22 673-678 | 1967 | El Paso County, Colorado, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
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Radiation - Copper Kα
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
10.6 Å | (100) |
3.51 Å | (80) |
2.77 Å | (60) |
2.64 Å | (60) |
2.57 Å | (60) |
9.82 Å | (30) |
1.76 Å | (30) |
Comments:
Låven Island, Norway. ICDD 14-194. Pattern is nearly identical to kupletskite.
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4b: Highly evolved igneous rocks | >3.0 |
35 : Ultra-alkali and agpaitic igneous rocks |
Geological Setting:
Nepheline syenites and alkali granites.
Type Occurrence of Astrophyllite
Place of Conservation of Type Material:
Mineralogische Sammlung der TU Bergakademie Freiberg.
Geological Setting of Type Material:
Nepheline-syenite pegmatite.
Synonyms of Astrophyllite
Other Language Names for Astrophyllite
Relationship of Astrophyllite to other Species
Member of:
Other Members of this group:
Bulgakite | Li2(Ca,Na)Fe2+7Ti2(Si4O12)2O2(OH)4(F,O)(H2O)2 | Tric. 1 : P1 |
Hydroastrophyllite | (H3O,K,Ca)3(Fe,Mn)5-65Ti2Si8(O,OH)31 | Tric. |
Nalivkinite | Li2Na(Fe2+,Mn2+)7Ti2Si8O26(OH)4F | Tric. 1 : P1 |
Niobophyllite | (K,Na)3(Fe,Mn)6(Nb,Ti)2Si8(O,OH,F)31 | Tric. |
Tarbagataite | (K◻)Ca(Fe2+,Mn)7Ti2(Si4O12)2O2(OH)5 | Tric. 1 : P1 |
Zircophyllite | K2NaFe2+7Zr2(Si4O12)2O2(OH)4F | Tric. |
Forms a series with:
Common Associates
Associated Minerals Based on Photo Data:
116 photos of Astrophyllite associated with Aegirine | NaFe3+Si2O6 |
91 photos of Astrophyllite associated with Quartz | SiO2 |
42 photos of Astrophyllite associated with Microcline | K(AlSi3O8) |
36 photos of Astrophyllite associated with Feldspar Group | |
34 photos of Astrophyllite associated with Albite | Na(AlSi3O8) |
21 photos of Astrophyllite associated with Zircon | Zr(SiO4) |
17 photos of Astrophyllite associated with Ferro-katophorite | {Na}{CaNa}{Fe2+4Al}[(AlSi7)O22](OH)2 |
17 photos of Astrophyllite associated with Aenigmatite | Na4[Fe2+10Ti2]O4[Si12O36] |
15 photos of Astrophyllite associated with Eudialyte | Na15Ca6Fe3Zr3Si(Si25O73)(O,OH,H2O)3(Cl,OH)2 |
14 photos of Astrophyllite associated with Riebeckite | ◻[Na2][Fe2+3Fe3+2]Si8O22(OH)2 |
Related Minerals - Strunz-mindat Grouping
9.DC. | Bulgakite | Li2(Ca,Na)Fe2+7Ti2(Si4O12)2O2(OH)4(F,O)(H2O)2 |
9.DC.05 | Hydroastrophyllite | (H3O,K,Ca)3(Fe,Mn)5-65Ti2Si8(O,OH)31 |
9.DC.05 | Kupletskite | (K,Na)3(Mn,Fe)7Ti2Si8O26(OH)4F |
9.DC.05 | Lobanovite | K2Na(Fe2+4Mg2Na)Ti2(Si4O12)2O2(OH)4 |
9.DC.05 | Niobophyllite | (K,Na)3(Fe,Mn)6(Nb,Ti)2Si8(O,OH,F)31 |
9.DC.05 | Zircophyllite | K2NaFe2+7Zr2(Si4O12)2O2(OH)4F |
9.DC.05 | Kupletskite-(Cs) | Cs2NaMn2+7Ti2(Si4O12)2O2(OH)4F |
9.DC.05 | Niobokupletskite | K2NaMn2+7(Nb,Ti)(Si4O12)2O2(OH)4(O,F) |
9.DC.05 | Nalivkinite | Li2Na(Fe2+,Mn2+)7Ti2Si8O26(OH)4F |
9.DC.05 | Devitoite | [Ba6(PO4)2(CO3)][Fe2+7(OH)4Fe3+2O2(Si4O12)2] |
9.DC.05 | Sveinbergeite | Ca(Fe2+6Fe3+)Ti2(Si4O12)2O2(OH)5(H2O)4 |
9.DC.05 | Tarbagataite | (K◻)Ca(Fe2+,Mn)7Ti2(Si4O12)2O2(OH)5 |
9.DC.05 | Heyerdahlite | Na3Mn7Ti2(Si4O12)2O2(OH)4F(H2O)2 |
9.DC.05 | Laverovite | K2NaMn7Zr2(Si4O12)2O2(OH)4F |
Other Information
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 Astrophyllite
mindat.org URL:
https://www.mindat.org/min-405.html
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References for Astrophyllite
Reference List:
Scheerer, Th. (1864) Ueber den Astrophyllit und sein Verhältniss zu Augit und Glimmer im Zirkonsyenit, nebst Bemerkungen über die plutonische Entstehung solcher Gebilde. Annalen der Physik und Chemie, 198. 107-138 doi:10.1002/andp.18641980507
Manning, P. G. (1969) On the origin of colour and pleochroism of astrophyllite and brown clintonite. The Canadian Mineralogist, 9 (5) 663-677
Fleischer, Michael, Chao, G. Y., Cabri, L. J. (1975) New mineral names. American Mineralogist, 60 (7-8) 736-739
Ma, Zhesheng, Li, Guowu, Shi, Nicheng, Zhou, Huyun, Ye, Danian, Pushcharovsky, D. Yu. (2001) Structure refinement of astrophyllite. Science in China Series D: Earth Sciences, 44 (6). 508-516 doi:10.1007/bf02876210
Piilonen, P. C., Lalonde, A. E., McDonald, A. M., Gault, R. A., Larsen, A. O. (2003) Insights into Astrophyllite-group minerals. I. Nomenclature, composition and development of standardized general formula. The Canadian Mineralogist, 41 (1) 1-26 doi:10.2113/gscanmin.41.1.1
Piilonen, P. C., McDonald, A. M., Lalonde, A. E. (2003) Insights into astrophyllite- group minerals. II. Crystal chemistry. The Canadian Mineralogist, 41 (1) 27-54 doi:10.2113/gscanmin.41.1.27
Cámara, Fernando, Sokolova, Elena, Abdu, Yassir, Hawthorne, Frank C. (2010) The crystal structures of niobophyllite, kupletskite-(Cs) and Sn-rich astrophyllite: revisios to the crystal chemistry of the astrophyllite-group minerals. The Canadian Mineralogist, 48 (1) 1-16 doi:10.3749/canmin.48.1.1
Sokolova, E. (2012) Further developments in the structure topology of the astrophyllite-group minerals. Mineralogical Magazine, 76 (4) 863-882 doi:10.1180/minmag.2012.076.4.04
Localities for Astrophyllite
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).
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.
All localities listed without proper references should be considered as questionable.
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