Megawite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Megawite
Helen D. Megaw
Formula:
CaSnO3
Colour:
Pale yellowish brown, pale yellow to colourless
Lustre:
Vitreous
Specific Gravity:
5.06 (Calculated)
Crystal System:
Orthorhombic
Name:
It is named in honour of the British crystallographer Helen Dick Megaw (1 June 1907, Dublin, Ireland - 26 February 2002, Ballycastle, Northern Ireland) who made significant contributions to our understanding of the structure and properties of natural and synthetic perovskites. In 1989, Megaw became the first woman to receive the Roebling Medal of the Mineralogical Society of America.
Type Locality:
Isostructural with:
Unique Identifiers
Mindat ID:
39893
Long-form identifier:
mindat:1:1:39893:8
IMA Classification of Megawite
Classification of Megawite
4.CC.30
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
C : Metal: Oxygen = 2: 3,3: 5, and similar
C : With large and medium-sized cations
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
C : Metal: Oxygen = 2: 3,3: 5, and similar
C : With large and medium-sized cations
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 |
|---|---|---|
| Mgw | 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 Megawite
Vitreous
Transparency:
Transparent
Colour:
Pale yellowish brown, pale yellow to colourless
Streak:
White
Cleavage:
Distinct/Good
on {110} and {001}
on {110} and {001}
Density:
5.06 g/cm3 (Calculated)
Optical Data of Megawite
Type:
Biaxial
RI values:
n = 1.89
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
Optical Extinction:
X = b; Y = a; Z = c.
Chemistry of Megawite
Mindat Formula:
CaSnO3
Element Weights:
Elements listed:
Crystallography of Megawite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pban
Cell Parameters:
a = 5.56(3) Å, b = 5.71(3) Å, c = 7.943(3) Å
Ratio:
a:b:c = 0.974 : 1 : 1.391
Unit Cell V:
252.17 ų (Calculated from Unit Cell)
Z:
4
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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
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
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
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) |
|---|---|---|---|---|---|---|---|
| 0018605 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 0 | 293 | |
| 0018625 | Megawite | Vegas A, Vallet-Regi M, Gonzalez-Calbet J M, Alario-Franco M A (1986) The ASnO3 (A = Ca, Sr) perovskites Acta Crystallographica B42 167-172 |  | 1986 | synthetic | 0 | 293 |
| 0018606 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 0.738 | 293 | |
| 0018607 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 1.5 | 293 | |
| 0018608 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 2.61 | 293 | |
| 0018609 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 3.94 | 293 | |
| 0018610 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 5.18 | 293 | |
| 0018611 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 5.98 | 293 | |
| 0018612 | Megawite | Zhao J, Ross N L, Angel R J (2004) Tilting and distortion of CaSnO3 perovskite to 7 GPa determined from single-crystal X-ray diffraction Physics and Chemistry of Minerals 31 299-305 | 2004 | synthetic | 6.73 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.984 Å | (52) |
| 3.970 Å | (19) |
| 2.855 Å | (43) |
| 2.812 Å | (100) |
| 2.780 Å | (19) |
| 1.992 Å | (13) |
| 1.985 Å | (13) |
| 1.640 Å | (13) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 9 : Lava/xenolith minerals (hornfels, sanidinite facies) |
Type Occurrence of Megawite
General Appearance of Type Material:
Either pseudo-cubic or pseudo-cuboctahedral crystals <15 µm in size, usually as inclusions in spurrite (Xenolith No. 1). Also as rims on µm-sized lakargiite crystals in larnite-cuspidine zones in skarns which contain abundant hydrogarnet and hydrosilicates.
Place of Conservation of Type Material:
Mineralogical Museum of Wrocław University, Poland under accession number MMUWrII16 717 and the Fersman Mineralogical Museum, Moscow, Russia under accession number 4021/1.
Geological Setting of Type Material:
It was found in the spurrite zone of skarned xenolith no. 1
(20-25 m in size) in ignimbrite.
(20-25 m in size) in ignimbrite.
Associated Minerals at Type Locality:
Synonyms of Megawite
Other Language Names for Megawite
Relationship of Megawite to other Species
Other Members of Perovskite Subgroup:
| Barioperovskite | BaTiO3 | Orth. mm2 : Amm2 |
| Goldschmidtite | KNbO3 | Iso. m3m(4/m32/m) : Pm3m |
| Isolueshite | (Na,La)NbO3 | Iso. m3m(4/m32/m) : Pm3m |
| Lakargiite | Ca(Zr,Sn,Ti)O3 | Orth. mmm(2/m2/m2/m) : Pnma |
| Loparite | (Na,REE)2Ti2O6 | Iso. m3m(4/m32/m) |
| Lueshite | NaNbO3 | Orth. mmm(2/m2/m2/m) |
| Macedonite | PbTiO3 | Tet. 4/mmm(4/m2/m2/m) : P4/nmm |
| Perovskite | CaTiO3 | Orth. mmm(2/m2/m2/m) : Pnma |
| Tausonite | SrTiO3 | Iso. 43m |
Common Associates
Associations Based on Photo Data:
| 1 photo of Megawite associated with Larnite | Ca2SiO4 |
| 1 photo of Megawite associated with Cuspidine | Ca8(Si2O7)2F4 |
| 1 photo of Megawite associated with Ettringite | Ca6Al2(SO4)3(OH)12 · 26H2O |
| 1 photo of Megawite associated with Perovskite | CaTiO3 |
Related Minerals - Strunz-mindat Grouping
| 4.CC. | Bernwoodite | Ca5TiAl2Si2O14 |
| 4.CC. | Xuite | Ca3Fe3+2[(AlO3(OH)]3 |
| 4.CC. | Yttriaite-(Y) | Y2O3 |
| 4.CC. | Allendeite | Sc4Zr3O12 |
| 4.CC. | Chlorkyuygenite | Ca12Al14O32[(H2O)4Cl2] |
| 4.CC. | Oboniobite | Mg4Nb2O9 |
| 4.CC. | Botuobinskite | SrFe2+Mg2(Cr3+6Ti4+12)[O36(OH)2] |
| 4.CC. | Mirnyite | SrZr4+Mg2(Cr3+6Ti4+12)O38 |
| 4.CC. | Haitaite-(La) | LaU4+Fe3+2(Ti13Fe2+4Fe3+)O38 |
| 4.CC. | Shagamite | KFe11O17 |
| 4.CC. | Bitikleite | Ca3(Sb5+Sn4+)[AlO4]3 |
| 4.CC. | Anzaite-(Ce) | Ce3+ 4Fe2+Ti6O18 (OH)2 |
| 4.CC. | Heamanite-(Ce) | (K0.5Ce0.5)TiO3 |
| 4.CC. | Priscillagrewite-(Y) | (Ca2Y)Zr2(AlO4)3 |
| 4.CC. | Strandite | Pb3Mn3+4Mn4+3O15 |
| 4.CC. | Saranovskite | SrCaFe2+2(Cr4Ti2)Ti12O38 |
| 4.CC.05 | Chrombismite | Bi3+16Cr6+O27 |
| 4.CC.10 | Freudenbergite | Na2(Ti,Fe)8O16 |
| 4.CC.10 | Fluormayenite | Ca12Al14O32F2 |
| 4.CC.10 | Fluorkyuygenite | Ca12Al14O32[(H2O)4F2] |
| 4.CC.15 | Grossite | CaAl4O7 |
| 4.CC.17 | Goldschmidtite | KNbO3 |
| 4.CC.20 | 'Unnamed (HBU UK-4)' | NaFe2+Zn2(Ti,Fe3+,Nb)6Ti12O38 |
| 4.CC.20 | Chlormayenite | Ca12Al14O32[◻4Cl2] |
| 4.CC.20 | Paseroite | PbMn2+(Mn2+,Fe3+)2(V5+,Ti,◻)18O38 |
| 4.CC.20 | Mianningite | (◻,Pb,Ce,Na)(U4+,Mn,U6+)Fe3+2 (Ti,Fe3+)18O38 |
| 4.CC.20 | 'UM1987-03-O:FePbTiU' | ~(U,Pb)(Ti,Fe3+,Fe2+,Mn)21O38 |
| 4.CC.22 | Gorerite | CaAlFe3+11O19 |
| 4.CC.22 | Kahlenbergite | KAl11O17 |
| 4.CC.25 | Hopmannite | Ba2(Ti5Fe)O13 |
| 4.CC.25 | Nixonite | Na2Ti6O13 |
| 4.CC.25 | Yafsoanite | Ca3Te6+2(ZnO4)3 |
| 4.CC.30 | Latrappite | Ca2NbFe3+O6 |
| 4.CC.30 | Natroniobite | NaNbO3 |
| 4.CC.30 | Perovskite | CaTiO3 |
| 4.CC.30 | Lueshite | NaNbO3 |
| 4.CC.30 | Bariolakargiite | BaZrO3 |
| 4.CC.30 | Barioperovskite | BaTiO3 |
| 4.CC.30 | Lakargiite | Ca(Zr,Sn,Ti)O3 |
| 4.CC.32 | Usturite | Ca3(Sb5+Zr)[Fe3+O4]3 |
| 4.CC.32 | Elbrusite | Ca3(U6+0.5Zr1.5)[Fe3+O4]3 |
| 4.CC.32 | Monteneveite | Ca3Sb5+2(Fe3+2Fe2+)O12 |
| 4.CC.32 | Dzhuluite | Ca3(Sb5+Sn4+)[Fe3+O4]3 |
| 4.CC.35 | Tausonite | SrTiO3 |
| 4.CC.35 | Loparite | (Na,REE)2Ti2O6 |
| 4.CC.35 | Panguite | (Ti,Al,Sc,Mg,Zr,Ca)1.8O3 |
| 4.CC.35 | Isolueshite | (Na,La)NbO3 |
| 4.CC.35 | Macedonite | PbTiO3 |
| 4.CC.37 | Pauloabibite | NaNbO3 |
| 4.CC.40 | Landauite | NaMnZn2(Ti,Fe)6Ti12O38 |
| 4.CC.40 | Mathiasite | (Mg,Cr,Fe,Ca,K)2(Ti,Zr,Cr,Fe)5O12 |
| 4.CC.40 | Senaite | Pb(Mn,Y,U)(Fe,Zn)2(Ti,Fe,Cr,V)18(O,OH)38 |
| 4.CC.40 | Gramaccioliite-(Y) | (Pb,Sr)(Y,Mn)Fe3+2(Ti,Fe3+)18O38 |
| 4.CC.40 | Lindsleyite | (Ba,Sr)(Zr,Ca)(Fe,Mg)2(Ti,Cr,Fe)18O38 |
| 4.CC.40 | Crichtonite | Sr(Mn,Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH)38 |
| 4.CC.40 | Loveringite | (Ca,Ce,La)(Zr,Fe)(Mg,Fe)2(Ti,Fe,Cr,Al)18O38 |
| 4.CC.40 | Cleusonite | (Pb,Sr)(U4+,U6+)(Fe2+,Zn)2(Ti,Fe2+,Fe3+)18(O,OH)38 |
| 4.CC.40 | Davidite-(Ce) | Ce(Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH,F)38 |
| 4.CC.40 | Davidite-(La) | La(Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH,F)38 |
| 4.CC.40 | 'Davidite-(Y)' | (La,Ce,Na,Ca,Pb)(Y,Fe2+,◻)(Fe2+,Mn2+)2(Ti,Fe3+,Nb,Zr)18O38 (hypothetical) |
| 4.CC.40 | 'Uhligite' | Ca3(Ti,Al,Zr)9O20 ? |
| 4.CC.40 | Dessauite-(Y) | (Sr,Pb)(Y,U)(Ti,Fe3+)20O38 |
| 4.CC.45 | Diaoyudaoite | NaAl11O17 |
| 4.CC.45 | Yimengite | K(Cr,Ti,Fe,Mg)12O19 |
| 4.CC.45 | Nežilovite | PbZn2Mn4+2Fe3+8O19 |
| 4.CC.45 | Hawthorneite | BaMgTi3Cr4Fe2+2Fe3+2O19 |
| 4.CC.45 | Mizraite-(Ce) | Ce(Al11Mg)O19 |
| 4.CC.45 | Haggertyite | BaFe2+4Fe3+2Ti5MgO19 |
| 4.CC.45 | Lindqvistite | Pb2Mn2+Fe16O27 |
| 4.CC.45 | Hibonite | CaAl12O19 |
| 4.CC.45 | Kangite | (Sc,Ti,Al,Zr,Mg,Ca,◻)2O3 |
| 4.CC.45 | Chihuahuaite | FeAl12O19 |
| 4.CC.45 | Barioferrite | BaFe3+12O19 |
| 4.CC.45 | Plumboferrite | Pb[Fe3+10.67Mn2+0.33Pb]O18.33 |
| 4.CC.45 | Batiferrite | BaTi2Fe3+8Fe2+2O19 |
| 4.CC.45 | Magnetoplumbite | PbFe3+12O19 |
| 4.CC.50 | Jeppeite | K2Ti6O13 |
| 4.CC.55 | Zenzénite | Pb3Fe3+4Mn4+3O15 |
| 4.CC.60 | 'Mengxianminite (of Huang et al.)' | (Ca,Na)3(Fe,Mn)2Mg2(Sn,Zn)5Al8O29 |
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 Megawite
mindat.org URL:
https://www.mindat.org/min-39893.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Megawite
Reference List:
Galuskin, E. V., Galuskina, I. O., Gazeev, V. M., Dzierżanowski, P., Prusik, K., Pertsev, N. N., Zadov, A. E., Bailau, R., Gurbanov, A. G. (2011) Megawite, CaSnO3: a new perovskite-group mineral from skarns of the Upper Chegem caldera, Kabardino-Balkaria, Northern Caucasus, Russia. Mineralogical Magazine, 75 (5) 2563-2572 doi:10.1180/minmag.2011.075.5.2563
Localities for Megawite
Showing 1 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.
Russia (TL) | |
| Galuskin et al. (2011) |
Quick NavTopAbout MegawiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Lakargi Mountain, Upper Chegem volcanic caldera, Chegemsky District, Kabardino-Balkaria, Russia