Macfallite
A valid IMA mineral species
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About Macfallite
Russell P. MacFall
Formula:
Ca2Mn3+3(SiO4)(Si2O7)(OH)3
Mn may be replaced by minor Al.
Colour:
Reddish-brown, maroon, dull pink
Lustre:
Sub-Adamantine, Silky
Hardness:
5
Specific Gravity:
3.43
Crystal System:
Monoclinic
Name:
Named in 1979 by Paul (Paulus) Brian Moore, Jun Ito, and Ian M. Steele in honor of Russell Patterson MacFall [1 September 1903 Indianapolis, Indiana, USA - 6 September 1983 Coronado, California, USA] editor for Chicago Tribune newspaper and, earlier, for other newspapers. Russ was an amateur mineralogist interested in systematic mineralogy and an author of six books on popular mineralogy, paleontology, and geology. Russ was also a specialist in the minerals of the region where macfallite was first discovered.
This page provides mineralogical data about Macfallite.
Unique Identifiers
Mindat ID:
2508
Long-form identifier:
mindat:1:1:2508:5
IMA Classification of Macfallite
Approved
Approval year:
1974
Classification of Macfallite
9.BG.15
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
58.2.3.2
58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
16.16.20
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
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 |
|---|---|---|
| Mcf | 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 Macfallite
Sub-Adamantine, Silky
Transparency:
Transparent, Translucent
Colour:
Reddish-brown, maroon, dull pink
Streak:
Brown with a reddish tint
Hardness:
5 on Mohs scale
Cleavage:
Perfect
{001}
{001}
Density:
3.43(2) g/cm3 (Measured) 3.53 g/cm3 (Calculated)
Optical Data of Macfallite
Type:
Biaxial (+/-)
RI values:
nα = 1.773 - 1.775 nβ = 1.795 nγ = 1.810 - 1.815
2V:
Measured: 86° , Calculated: 78° to 88°
Max. Birefringence:
δ = 0.037 - 0.040
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate
Dispersion:
r < v medium
Pleochroism:
Visible
Comments:
X = colorless to yellow; Y = light brown; Z = dark brown to reddish brown.
Comments:
2V(meas.) = Very large
Chemistry of Macfallite
Mindat Formula:
Ca2Mn3+3(SiO4)(Si2O7)(OH)3
Mn may be replaced by minor Al.
Mn may be replaced by minor Al.
Element Weights:
Common Impurities:
Ti,Al,Fe,Cr,V,Cu,Mg,K,Na,H2O
Crystallography of Macfallite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Setting:
P21/m
Cell Parameters:
a = 10.235(3) Å, b = 6.086(6) Å, c = 8.970(5) Å
β = 110.75(3)°
β = 110.75(3)°
Ratio:
a:b:c = 1.682 : 1 : 1.474
Unit Cell V:
522.50 ų (Calculated from Unit Cell)
Z:
2
Twinning:
By reflection on {100}, commonly repeated.
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) |
|---|---|---|---|---|---|---|---|
| 0004767 | Macfallite | Nagashima M, Rahmoun N S, Alekseev E V, Geiger C A, Armbruster T, Akasaka M (2008) Crystal chemistry of macfallite: Relationships to sursassite and pumpellyite American Mineralogist 93 1851-1857 |  | 2008 | Manganese Lake, Copper Harbor, Keweenaw County, Michigan | 0 | 293 |
| 0000966 | Macfallite | Moore P B, Shen J, Araki T (1985) Crystal chemistry of the (M2)3+ phi2 sheet: Structural principles and crystal structures of ruizite, macfallite and orientite American Mineralogist 70 171-181 | | 1985 | Lake Manganese, Copper Harbor, Keweenaw County, Michigan, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.70 Å | (100) |
| 4.76 Å | (90) |
| 1.588 Å | (85) |
| 3.904 Å | (80) |
| 3.40 Å | (70) |
| 2.97 Å | (70) |
| 2.18 Å | (70) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Type Occurrence of Macfallite
General Appearance of Type Material:
radial and framboidal aggregates
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 135923; The Natural History Museum, London, England, 1984,139.
Associated Minerals at Type Locality:
Synonyms of Macfallite
Other Language Names for Macfallite
Common Associates
Associations Based on Photo Data:
| 22 photos of Macfallite associated with Calcite | CaCO3 |
| 19 photos of Macfallite associated with Orientite | Ca8Mn3+10(SiO4)3(Si3O10)3(OH)10 · 4H2O |
| 10 photos of Macfallite associated with Braunite | Mn2+Mn3+6(SiO4)O8 |
| 2 photos of Macfallite associated with Neltnerite | CaMn3+6(SiO4)O8 |
| 1 photo of Macfallite associated with Pyrolusite | Mn4+O2 |
| 1 photo of Macfallite associated with Ranciéite | (Ca,Mn2+)0.2(Mn4+,Mn3+)O2 · 0.6H2O |
Related Minerals - Strunz-mindat Grouping
| 9.BG. | Alumovesuvianite | Ca19AlAl4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
| 9.BG. | Alnaperbøeite-(Ce) | Ca(Ce2.5Na0.5)(AlAl2Al)[Si2O7][SiO4]3O(OH)2 |
| 9.BG. | Zilbermintsite-(La) | (CaLa5)(Fe3+Al3Fe2+)[Si2O7][SiO4]5O(OH)3 |
| 9.BG. | Heflikite | (CaCa)(AlAlSc)O[Si2O7][SiO4](OH) |
| 9.BG. | Magnesiovesuvianite | Ca19MgAl4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG. | Zoisite-(Pb) | (CaPb)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG. | Shuiskite-(Cr) | Ca2Cr3+Cr3+2[Si2O6OH][SiO4](OH)2O |
| 9.BG. | Radekškodaite Group | |
| 9.BG.05 | Dissakisite-(La) | (CaLa)(AlAlMg)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Manganiandrosite-(Ce) | (Mn2+Ce)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Dissakisite-(Ce) | (CaCe)(AlAlMg)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Sm) | (CaSm)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Hancockite | (CaPb)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Dollaseite-(Ce) | (CaCe)(MgAlMg)F[Si2O7][SiO4](OH) |
| 9.BG.05a v | 'Unnamed (Ga-analogue of Epidote)' | (CaCa)(AlAlGa3+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Clinozoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Epidote-(Sr) | (CaSr)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Vanadoandrosite-(Ce) | (Mn2+Ce)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Vanadoallanite-(La) | (CaLa)(V3+AlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | 'Unnamed (Mg-analogue of Ferriallanite-(Ce))' | (CaCe)(Fe3+AlMg)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriallanite-(La) | (CaLa)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Uedaite-(Ce) | (Mn2+Ce)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Tweddillite | (CaSr)(Mn3+AlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Åskagenite-(Nd) | (Mn2+Nd)(AlAlFe3+)O[Si2O7][SiO4]O |
| 9.BG.05 | Piemontite-(Pb) | (CaPb)(AlAlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Ce) | (CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(La) | (CaLa)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Y) | (CaY)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Piemontite | (CaCa)(AlAlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Akasakaite-(Ce) | (CaCe)(AlAlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Manganiandrosite-(La) | (Mn2+La)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Akasakaite-(La) | (CaLa)(AlAlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Vanadoakasakaite-(La) | (CaLa)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Khristovite-(Ce) | (CaCe)(MgAlMn2+)F[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriakasakaite-(La) | (CaLa)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Ferriandrosite-(La) | (Mn2+La)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | 'Androsite-(Ce)' | (Mn2+Ce)(AlAlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Vielleaureite-(Ce) | Mn2+Ce(MgAlMn2+)(Si2O7)(SiO4)F(OH) |
| 9.BG.05 | Ferriandrosite-(Ce) | (Mn2+Ce)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriallanite-(Ce) | (CaCe)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | 'Unnamed (Mn3+-analogue of Ferriakasakaite-(Ce))' | (CaCe)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Vanadoakasakaite-(Ce) | (CaCe)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Piemontite-(Sr) | (CaSr)(AlAlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Niigataite | (CaSr)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriakasakaite-(Ce) | (CaCe)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Nd) | (CaNd)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | 'UM1989-32-SiO:AlCaFeHREE' | (Ca0.5◻0.5REE)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Mukhinite | (CaCa)(AlAlV3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Manganiakasakaite-(La) | (CaLa)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.10 | Zoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG.15 | Sursassite | Mn2+2Al3(SiO4)(Si2O7)(OH)3 |
| 9.BG.20 | Pumpellyite-(Al) | Ca2AlAl2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Shuiskite-(Mg) | Ca2MgCr3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Julgoldite-(Fe2+) | Ca2Fe2+Fe3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Okhotskite | Ca2Mn2+Mn3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Julgoldite-(Mg) | Ca2MgFe3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Poppiite | Ca2V3+V3+2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Julgoldite-(Fe3+) | Ca2Fe3+Fe3+2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Pumpellyite-(Fe2+) | Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Pumpellyite-(Fe3+) | Ca2Fe3+Al2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Pumpellyite-(Mg) | Ca2MgAl2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Pumpellyite-(Mn2+) | Ca2Mn2+Al2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.25 | Ganomalite | Pb9Ca5Mn(Si2O7)4(SiO4)O |
| 9.BG.25 | Wayneburnhamite | Pb9Ca6(Si2O7)3(SiO4)3 |
| 9.BG.30 | Rustumite | Ca10(Si2O7)2(SiO4)(OH)2Cl2 |
| 9.BG.35 | Modraite | Ca19Fe2+Al4(Al6Fe2+2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG.35 | Fluorvesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(F,OH)9 |
| 9.BG.35 | Vesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
| 9.BG.35 | Milanriederite | (Ca18[REE])Fe3+Al4(Mg4Al4)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG.35 | Manaevite-(Ce) | (Ca13Ce4[H2O]2)Mg(Al3Mg)(Mg3Ti3Fe3+2)(◻4)◻[Si2O7]4[(SiO4)8(H4O4)2]O(OH)9 |
| 9.BG.35 | Hongheite | Ca19Fe2+Al4(Fe3+,Mg)8(◻4)B[Si2O7]4[(SiO4)10]O(OH,O)9 |
| 9.BG.35 | Wiluite | Ca19MgAl4(Al,Mg)8(B,◻)4◻[Si2O7]4[(SiO4)10]O(O,OH)9 |
| 9.BG.35 | Cyprine | Ca19Cu2+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG.35 | Manganvesuvianite | Ca19Mn3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
| 9.BG.40 | Vyuntspakhkite-(Y) | (Y,Yb)4Al2.5-1.5(Si,Al)1.5-2.5(SiO4)4O(OH)7 |
| 9.BG.45 | Dellaite | Ca6Si3O11(OH)2 |
| 9.BG.50 | Ferriperbøeite-(Ce) | CaCe3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Perbøeite-(La) | CaLa3(AlAl2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Perbøeite-(Ce) | CaCe3(AlAl2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Gatelite-(Ce) | CaCe3(AlAl2Mg)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Ferriperbøeite-(La) | CaLa3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.55 | Västmanlandite-(Ce) | CaCe3(MgAl2Mg)[Si2O7][SiO4]3F(OH)2 |
| 9.BG.60 | Radekškodaite-(La) | (CaLa5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 |
| 9.BG.60 | Radekškodaite-(Ce) | (CaCe5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 |
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 Macfallite
mindat.org URL:
https://www.mindat.org/min-2508.html
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References for Macfallite
Reference List:
Moore, Paul B., Ito, Jun, Steele, Ian M. (1979) MacFallite and orientite: calcium manganese (III) silicates from upper Michigan. Mineralogical Magazine, 43 (327) 325-331 doi:10.1180/minmag.1979.043.327.02
Fleischer, Michael, Cabri, Louis J., Pabst, Adolf (1980) New Mineral Names. American Mineralogist, 65 (3-4) 406-408
Moore, Paul B., Shen, Jinchuan, Araki, Takaharu (1985) Crystal chemistry of the 2∞[M3+2φ2(TO4)2] sheet: structural principles and crystal structures of ruizite, macfallite and orientite. American Mineralogist, 70 (1-2) 171-181
Nagashima, M., Rahmoun, N.-S., Alekseev, E. V., Geiger, C. A., Armbruster, T., Akasaka, M. (2008) Crystal chemistry of macfallite: Relationships to sursassite and pumpellyite. American Mineralogist, 93 (11) 1851-1857 doi:10.2138/am.2008.2935
Localities for Macfallite
Showing 7 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.
Italy | |
| Frank K. Mazdab collection (see https://www.rockptx.com/fkm-151-to-fkm-175/#FKM-171 for analytical data) +1 other reference |
| Castellaro et al. (2023) |
| Palenzona (1990) |
Japan | |
| Miyajima et al. (1994) |
Serbia | |
| Pačevski et al. (2016) +1 other reference |
USA (TL) | |
| Moore et al. (1979) +2 other references |
| Steven Kuitems |
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Manganese Mine, Copper Harbor, Grant Township, Keweenaw County, Michigan, USA