Lobanovite (original) (raw)
A valid IMA mineral species
About LobanoviteHide
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Formula:
K2Na(Fe2+4Mg2Na)Ti2(Si4O12)2O2(OH)4
Colour:
Straw yellow to orange
Specific Gravity:
3.161 (Calculated)
Crystal System:
Monoclinic
Name:
First described in 1959 as "unusual light yellow and greenish fibrous astrophyllite" by E.I. Semenov from Kukisvumchorr Mt, Khibiny, Kola, Russia (Pekov 1998). Named magnesium astrophyllite for its relationship to astrophyllite and changed in 2008 to magnesioastrophyllite. It was formally described as a new mineral in 2017 (Sokolova et al.). The name lobanovite honors Dr. Constantin V. Lobanov, a Russian geologist working in the Kola Peninsula.
Unique combination of elements.
Note:
Originally named and published as "magnesium astrophyllite" and "magnesioastrophyllite". Validated by IMA in 2015 under the name lobanovite (IMA 15-B).
Peng & Ma (1963) established its monoclinic symmetry.
The structure is based on HOH blocks comprising one cp octahedral and two heteropolyhedral sheets; the HOH blocks repeat along [001]. The O sheet is built of M(1-4) octahedra; the H sheet is formed by T4O12 astrophyllite ribbons having common vertices with D polyhedra dominated by VTi. K and Na atoms are in the interstitial A and B sites.
Unique IdentifiersHide
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Long-form identifier:
mindat:1:1:2487:3
21407191-5462-469d-b8a3-e8025bd7d297
IMA Classification of LobanoviteHide
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Approval history:
IMA 15-B: "magnesioastrophyllite" is validated under the name lobanovite (Hålenius et al. 2015).
Classification of LobanoviteHide
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9.DC.05
9 : SILICATES (Germanates)
D : Inosilicates
C : Inosilicates with branched 2-periodic single chains; Si2O6 + 2SiO3 Si4O12
69.1.1.7
69 : INOSILICATES Chains with Side Branches or Loops
1 : Chains with Side Branches or Loops with (P=2, and N=4, 2 branches)
14.9.31
14 : Silicates not Containing Aluminum
9 : Silicates of Ti
Mineral SymbolsHide
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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.
| Symbol | Source | Reference |
|---|---|---|
| Lbv | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Lbv | 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 LobanoviteHide
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Colour:
Straw yellow to orange
Streak:
White to yellowish-white.
Cleavage:
Perfect
Perfect cleavage parallel to (001) and moderate cleavage parallel to (010).
Density:
3.161 g/cm3 (Calculated)
Comment:
Calculated from the empirical formula.
Optical Data of LobanoviteHide
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RI values:
_n_α = 1.658 _n_β = 1.687 _n_γ = 1.710
2V:
Measured: 81.5° to 83°, Calculated: 82°
δ = 0.052
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Dispersion:
r < v, strong.
Optical Extinction:
Y = b; Z ∧ a = –5 to –6°.
Comments:
X = bright yellow; Y = pale yellowish grey; Z = grey.
Comments:
Absorption: Z < Y < X.
Chemistry of LobanoviteHide
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Mindat Formula:
K2Na(Fe2+4Mg2Na)Ti2(Si4O12)2O2(OH)4
Common Impurities:
Mn,F,Ca,(Nb,Al,Ba)
Crystallography of LobanoviteHide
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Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 5.3327(2) Å, b = 23.1535(9) Å, c = 10.3775(4) Å
β = 99.615(1)°
Ratio:
a:b:c = 0.23 : 1 : 0.448
Morphology:
Elongated blades.
Crystal StructureHide
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| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0009902 | Lobanovite | Shi N, Ma Z, Li G, Yamnova M A, Pushcharovsky D Y (1998) Structure refinement of monoclinic astrophyllite Acta Crystallographica B54 109-114 |  |
1998 | Khibina alkaline massif, Russia | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder DiffractionHide
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Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.38 100 Å | (003) |
| 2.548 90 Å | (063) |
| 10.1 80 Å | (001) |
| 3.80 60 Å | (042 131) |
| 3.079 50 Å | (132 062) |
| 2.763 90 Å | (⎯171) |
Comments:
The data are given in Sokolova et al. (2017) but are from the X-ray Laboratory, Hubei Geologic College (1974).
Geological EnvironmentHide
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Type Occurrence of LobanoviteHide
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General Appearance of Type Material:
Elongated bladed crystals up to 0.04 mm wide and 0.2 mm long.
Geological Setting of Type Material:
Associated Minerals at Type Locality:
Synonyms of LobanoviteHide
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Relationship of Lobanovite to other SpeciesHide
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Other Members of this group:
| Devitoite | [Ba6(PO4)2(CO3)][Fe2+7(OH)4Fe3+2O2(Si4O12)2] | Tric. 1 : _P_1 |
|---|---|---|
| Sveinbergeite | Ca(Fe2+6Fe3+)Ti2(Si4O12)2O2(OH)5(H2O)4 | Tric. 1 : _P_1 |
Common AssociatesHide
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Associated Minerals Based on Photo Data:
Related Minerals - Strunz-mindat GroupingHide
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| 9.DC. | Bulgakite | Li2(Ca,Na)Fe2+7Ti2(Si4O12)2O2(OH)4(F,O)(H2O)2 | Tric. 1 : _P_1 |
|---|---|---|---|
| 9.DC.05 | Astrophyllite | K2NaFe2+7Ti2Si8O26(OH)4F | Tric. 1 : _P_1 |
| 9.DC.05 | Hydroastrophyllite | (H3O,K,Ca)3(Fe,Mn)5-65Ti2Si8(O,OH)31 | Tric. |
| 9.DC.05 | Kupletskite | (K,Na)3(Mn,Fe)7Ti2Si8O26(OH)4F | Tric. |
| 9.DC.05 | Niobophyllite | (K,Na)3(Fe,Mn)6(Nb,Ti)2Si8(O,OH,F)31 | Tric. |
| 9.DC.05 | Zircophyllite | K2NaFe2+7Zr2(Si4O12)2O2(OH)4F | Tric. |
| 9.DC.05 | Kupletskite-(Cs) | Cs2NaMn2+7Ti2(Si4O12)2O2(OH)4F | Tric. 1 : _P_1 |
| 9.DC.05 | Niobokupletskite | K2NaMn2+7(Nb,Ti)(Si4O12)2O2(OH)4(O,F) | Tric. 1 : _P_1 |
| 9.DC.05 | Nalivkinite | Li2Na(Fe2+,Mn2+)7Ti2Si8O26(OH)4F | Tric. 1 : _P_1 |
| 9.DC.05 | Devitoite | [Ba6(PO4)2(CO3)][Fe2+7(OH)4Fe3+2O2(Si4O12)2] | Tric. 1 : _P_1 |
| 9.DC.05 | Sveinbergeite | Ca(Fe2+6Fe3+)Ti2(Si4O12)2O2(OH)5(H2O)4 | Tric. 1 : _P_1 |
| 9.DC.05 | Tarbagataite | (K◻)Ca(Fe2+,Mn)7Ti2(Si4O12)2O2(OH)5 | Tric. 1 : _P_1 |
| 9.DC.05 | Heyerdahlite | Na3Mn7Ti2(Si4O12)2O2(OH)4F(H2O)2 | Tric. 1 : _P_1 |
| 9.DC.05 | Laverovite | K2NaMn7Zr2(Si4O12)2O2(OH)4F | Tric. 1 : _P_1 |
Other InformationHide
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Thermal Behaviour:
The DTA curve shows endothermic peaks at 835°C (strong, escape of OH) and 900°C (weak).
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 LobanoviteHide
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References for LobanoviteHide
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Reference List:
Sokolova, Elena, Cámara, Fernando, Hawthorne, Frank C., Semenov, Evgeny I., Ciriotti, Marco E. (2017) Lobanovite, K2Na(Fe42+Mg2Na)Ti2(Si4O12)2O2(OH)4, a new mineral of the astrophyllite supergroup and its relation to magnesioastrophyllite. Mineralogical Magazine, 81 (1) 175-181 doi:10.1180/minmag.2016.080.088
Localities for LobanoviteHide
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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
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