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Macaulayite

A valid IMA mineral species
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00363140017881598437529.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
07429300017776688267692.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
00340950017776688272259.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
06300120017881597968837.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
07667510017271924867016.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
03322300017776681322835.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
04458470017881598297379.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
01826360017776688274203.jpg
Macaulayite

Bennachie, Inverurie, Aberdeenshire, Scotland, UK
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About MacaulayiteHide

05856120017271924936438.jpg
Maucauley Institute
Formula:
(Fe,Al)24Si4O43(OH)2
In the type material, Fe:Al is approximately 13:1.
Colour:
Red
Lustre:
Earthy
Specific Gravity:
4.41 (Calculated)
Crystal System:
Monoclinic
Name:
Named in 1984 by M.J. Wilson, J.D. Russell, J.M. Tait, D.R. Clark, and A.R. Fraser for the Macaulay Institute of Soil Research, Aberdeen, Scotland, UK. The Macauley Institute became a part of Hutton Institute on April 1, 2011.
A swelling iron phyllo-silicate mineral, thought to be composed of layers consisting of twelve iron-oxygen octahedral sheets (equivalent to two hematite unit cells) flanked by two tetrahedral silicate sheets, one on the top and one at the bottom.

Recent research (2009) at NASA has speculated that this mineral may be a significant indicator for the historical presence and distribution of water on Mars.


Unique IdentifiersHide

Mindat ID:
2505
Long-form identifier:
mindat:1:1:2505:4

IMA Classification of MacaulayiteHide

Classification of MacaulayiteHide

Strunz-mindat (2026):
9.EC.65

9 : SILICATES (Germanates)
E : Phyllosilicates
C : Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
Dana 8th ed.:
71.2.5.1

71 : PHYLLOSILICATES Sheets of Six-Membered Rings
2 : Sheets of 6-membered rings with 2:1 layers
Hey's CIM Ref.:
16.17.2

16 : Silicates Containing Aluminum and other Metals
17 : Aluminosilicates of Fe

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
McyIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of MacaulayiteHide

Lustre:
Earthy
Transparency:
Translucent
Colour:
Red
Density:
4.41 g/cm3 (Calculated)

Optical Data of MacaulayiteHide

Type:
Biaxial
RI values:
nα = 1.734
Surface Relief:
Unknown
Dispersion:
r > v
Comments:
n = > 1.74

Chemistry of MacaulayiteHide

Mindat Formula:
(Fe,Al)24Si4O43(OH)2

In the type material, Fe:Al is approximately 13:1.
Element Weights:
Element% weight
Fe61.633 %
O33.108 %
Si5.166 %
H0.093 %

Calculated from ideal end-member formula.
Fe
O
Si
H
Elements listed:
Al, Fe, H, O, Si - search for minerals with similar chemistry
Common Impurities:
H2O

Crystallography of MacaulayiteHide

Crystal System:
Monoclinic
Cell Parameters:
a = 5.038 Å, b = 8.726 Å, c = 36.342 Å
β = 92°
Ratio:
a:b:c = 0.577 : 1 : 4.165
Unit Cell V:
1,596.68 ų (Calculated from Unit Cell)
Z:
2
Comment:
Point Group: n.d.; Space Group: C-centered cell

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
36.6 Å(vs)
18.16 Å(vs)
2.533 Å(100)
2.720 Å(35)
1.462 Å(35)
3.700 Å(25)
2.214 Å(20)
Comments:
strongest two lines from oriented sample. Basal planes expand after glycol treatment

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]

Type Occurrence of MacaulayiteHide

Type Locality:
ⓘ Bennachie, Inverurie, Aberdeenshire, Scotland, UK
Place of Conservation of Type Material:
Royal Scottish Museum, Edinburgh, Scotland.
The Natural History Museum, London, England.
Geological Setting of Type Material:
Formed in the breakdown and weathering of granites in tropical conditions.
Associated Minerals at Type Locality:
Kaolinite'Illite'
Reference:
Wilson, M. J., Russell, J. D., Tait, J. M., Clark, D. R., Fraser, A. R. (1984) Macaulayite, a new mineral from North-East Scotland. Mineralogical Magazine, 48 (346) 127-129 doi:10.1180/minmag.1984.048.346.17

Synonyms of MacaulayiteHide

Other Language Names for MacaulayiteHide

Related Minerals - Strunz-mindat GroupingHide

9.EC.MeifuiteKFe6(Si7Al)O19(OH)4Cl2Tric. 1 : P1
9.EC.BalestraiteKLi2V5+Si4O12Mon. 2 : B2
9.EC.05TalcMg3Si4O10(OH)2Tric. 1 : P1
9.EC.05MinnesotaiteFe2+3Si4O10(OH)2Tric. 1 : P1
9.EC.05WillemseiteNi3Si4O10(OH)2Mon.
9.EC.9.EC.VoloshiniteRb(LiAl1.5◻0.5)(Al0.5Si3.5)O10F2Mon. 2/m : B2/b
9.EC.10FluorluanshiweiiteKLiAl1.5(Si3.5Al0.5)O10F2Mon. 2/m : B2/m
9.EC.10GarmiteCsLiMg2(Si4O10)F2Mon.
9.EC.10GorbunoviteCsLi2(Ti,Fe)Si4O10(F,OH,O)2Mon.
9.EC.10FerripyrophylliteFe3+Si2O5(OH)Mon. 2/m
9.EC.10ManganiceladoniteK(MgMn3+◻)(Si4O10)(OH)2Mon.
9.EC.10LuanshiweiiteKLiAl1.5(Si3.5Al0.5)O10(OH)2Mon. 2/m : B2/b
9.EC.10PyrophylliteAl2Si4O10(OH)2Tric. 1
9.EC.15ParagoniteNaAl2(AlSi3O10)(OH)2Mon.
9.EC.15FerroaluminoceladoniteK(Fe2+Al◻)(Si4O10)(OH)2Mon. 2/m : B2/m
9.EC.15NanpingiteCsAl2(AlSi3O10)(OH,F)2Mon. 2/m : B2/b
9.EC.15FerroceladoniteK(Fe2+Fe3+◻)(Si4O10)(OH)2Mon. 2/m : B2/m
9.EC.15GanteriteBa0.5(Na,K)0.5Al2(Si2.5Al1.5)O10(OH)2Mon. 2/m : B2/b
9.EC.15KreiteriteCsLi2Fe3+(Si4O10)F2Mon.
9.EC.15RoscoeliteKV3+2(AlSi3O10)(OH)2Mon. 2/m : B2/b
9.EC.15AluminoceladoniteK(MgAl◻)(Si4O10)(OH)2Mon. 2/m : B2/m
9.EC.15Tobelite(NH4)Al2(AlSi3O10)(OH)2Mon. 2/m : B2/m
9.EC.15TainioliteKLiMg2(Si4O10)F2Mon. 2/m : B2/m
9.EC.15CeladoniteK(MgFe3+◻)(Si4O10)(OH)2Mon. 2/m : B2/m
9.EC.15ChromceladoniteK(MgCr◻)(Si4O10)(OH)2Mon. 2 : B2
9.EC.15MontdoriteKFe2+1.5Mn2+0.5Mg0.5Si4O10(F,OH)2Mon. 2/m : B2/m
9.EC.15ChromphylliteKCr2(AlSi3O10)(OH)2Mon. 2/m : B2/b
9.EC.15BoromuscoviteKAl2(BSi3O10)(OH)2Mon. 2/m
9.EC.15'UM1988-22-SiO:AlCaFFeHKLiMg'KLiMgAl2Si3O10F2Mon.
9.EC.15Chernykhite(Ba,Na)(V3+,Al,Mg)2((Si,Al)4O10)(OH)2Mon.
9.EC.15MuscoviteKAl2(AlSi3O10)(OH)2Mon. 2/m : B2/b
9.EC.20MasutomiliteK(LiAlMn2+)[AlSi3O10]F2Mon. 2 : B2
9.EC.20OxyphlogopiteK(Mg,Ti,Fe)3[(Si,Al)4O10](O,F)2Mon. 2/m : B2/m
9.EC.20'Chloroferrokinoshitalite'(Ba,K)(Fe2+,Mg)3(Al2Si2O10)(Cl,OH,F)2
9.EC.20SiderophylliteKFe2+2Al(Al2Si2O10)(OH)2Mon.
9.EC.20SokolovaiteCsLi2Al(Si4O10)F2Mon.
9.EC.20HendricksiteKZn3(Si3Al)O10(OH)2Mon. 2/m : B2/m
9.EC.20TetraferriphlogopiteKMg3(Si3Fe3+)O10(OH)2Mon. 2/m : B2/m
9.EC.20FluoranniteKFe2+3(Si3Al)O10F2Mon. 2/m : B2/m
9.EC.20AspidoliteNaMg3(AlSi3O10)(OH)2Mon. 2/m : B2/m
9.EC.20Suhailite(NH4)Fe2+3(AlSi3O10)(OH)2Mon. 2/m : B2/m
9.EC.20EphesiteNaLiAl2(Al2Si2O10)(OH)2Tric. 1 : P1
9.EC.20NorrishiteKLiMn3+2(Si4O10)O2Mon. 2/m : B2/m
9.EC.20PhlogopiteKMg3(AlSi3O10)(OH)2Mon. 2/m : B2/m
9.EC.20YangzhumingiteKMg2.5(Si4O10)F2Mon. 2/m : B2/m
9.EC.20OrloviteKLi2Ti(Si4O10)OFMon. 2 : B2
9.EC.20TetraferrianniteKFe2+3(Si3Fe3+)O10(OH)2Mon. 2/m : B2/m
9.EC.20ShirokshiniteK(NaMg2)(Si4O10)F2Mon. 2/m : B2/m
9.EC.20TrilithioniteK(Li1.5Al1.5)(AlSi3O10)(F,OH)2Mon. 2/m : B2/b
9.EC.20PolylithioniteKLi2Al(Si4O10)(F,OH)2Mon. 2/m : B2/b
9.EC.20ShirozuliteKMn2+3(Si3Al)O10(OH)2Mon. 2/m : B2/m
9.EC.20PreiswerkiteNaMg2Al(Al2Si2O10)(OH)2Mon. 2/m : B2/b
9.EC.20FluorophlogopiteKMg3(Si3Al)O10F2Mon. 2/m : B2/m
9.EC.20Wonesite(Na,K,◻)(Mg,Fe,Al)6(Si,Al)8O20(OH,F)4Mon. 2/m : B2/m
9.EC.20'UM2004-49-SiO:AlCsFHKLi'(Cs,K)(Al,Li)2.6((Si,Al)4O10)(F,OH)2
9.EC.20FluorotetraferriphlogopiteKMg3(Fe3+Si3O10)F2Mon. 2/m : B2/m
9.EC.20AnniteKFe2+3(AlSi3O10)(OH)2Mon. 2/m : B2/m
9.EC.20EastoniteKMg2Al(Al2Si2O10)(OH)2Mon.
9.EC.22'Pimelite'Ni3Si4O10(OH)2 · 4H2OHex.
9.EC.30MargariteCaAl2(Al2Si2O10)(OH)2Mon. 2/m : B2/b
9.EC.35Kinoshitalite(Ba,K)(Mg,Mn2+,Al)3(Al2Si2O10)(OH)2Mon. 2/m : B2/m
9.EC.35Ferrokinoshitalite(Ba,K)(Fe2+,Mg)3(Al2Si2O10)(OH,F)2Mon. 2/m : B2/m
9.EC.35ClintoniteCaAlMg2(SiAl3O10)(OH)2Mon. 2/m : B2/m
9.EC.35Oxykinoshitalite(Ba,K)(Mg,Ti,Fe3+,Fe2+)3((Si,Al)4O10)(O,OH,F)2Mon. 2/m : B2/m
9.EC.35FluorokinoshitaliteBaMg3(Al2Si2O10)F2Mon. 2/m : B2/m
9.EC.35BityiteCaLiAl2(AlBeSi2O10)(OH)2Mon. 2/m : B2/b
9.EC.35Anandite(Ba,K)(Fe2+,Mg)3((Si,Al,Fe)4O10)(S,OH)2Mon. 2/m : B2/b
9.EC.40Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2OMon. 2/m : B2/m
9.EC.40Beidellite(Na,Ca0.5)0.3Al2((Si,Al)4O10)(OH)2 · nH2OMon. 2/m : B2/m
9.EC.40VolkonskoiteCa0.3(Cr,Mg,Fe)2((Si,Al)4O10)(OH)2 · 4H2OMon.
9.EC.40NontroniteNa0.3Fe2((Si,Al)4O10)(OH)2 · nH2OMon. 2/m : B2/m
9.EC.40Kurumsakite(Zn,Ni,Cu)8Al8V5+2Si5O35 · 27H2O (?)Orth.
9.EC.40Yakhontovite(Ca,Na)0.5(Cu,Fe,Mg)2(Si4O10)(OH)2 · 3H2OMon.
9.EC.45SwineforditeLi(Al,Li,Mg)3((Si,Al)4O10)2(OH,F)4 · nH2OMon. 2/m : B2/m
9.EC.45HectoriteNa0.3(Mg,Li)3(Si4O10)(F,OH)2Mon. 2/m : B2/m
9.EC.45ZincsiliteZn3Si4O10(OH)2 · 4H2O (?)Mon.
9.EC.45HanjiangiteBa2CaV3+Al(H2AlSi3O12)(CO3)2FMon. 2 : B2
9.EC.45SpadaiteMgSiO2(OH)2 · H2O (?)
9.EC.45FerrosaponiteCa0.3(Fe2+,Mg,Fe3+)3((Si,Al)4O10)(OH)2 · 4H2OMon.
9.EC.45Stevensite(Ca,Na)xMg3-x(Si4O10)(OH)2Mon.
9.EC.45SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2OMon.
9.EC.45SauconiteNa0.3Zn3((Si,Al)4O10)(OH)2 · 4H2OMon.
9.EC.50VermiculiteMg0.7(Mg,Fe,Al)6(Si,Al)8O20(OH)4 · 8H2OMon. 2/m
9.EC.52'Tarasovite'near NaKAl11Si13O40(OH)9 · 3H2O
9.EC.55ClinochloreMg5Al(AlSi3O10)(OH)8Mon. 2/m : B2/m
9.EC.55Borocookeite(LiAl4◻)[BSi3O10](OH)8Mon. m : Bb
9.EC.55FranklinfurnaceiteCa2Fe3+Mn2+3Mn3+(Zn2Si2O10)(OH)8Mon. 2 : B2
9.EC.55PennantiteMn2+5Al(AlSi3O10)(OH)8Tric.
9.EC.55VakhrushevaiteMg5Cr(AlSi3O10)(OH)8Tric. 1
9.EC.55NimiteNi5Al(AlSi3O10)(OH)8Mon. 2/m : B2/m
9.EC.55Cookeite(LiAl4◻)[AlSi3O10](OH)8Mon. 2/m
9.EC.55GonyeriteMn2+5Fe3+(Fe3+Si3O10)(OH)8Orth.
9.EC.55ChamositeFe2+5Al(AlSi3O10)(OH)8Mon. 2/m : B2/m
9.EC.55'Orthochamosite'(Fe2+,Mg,Fe3+)5Al(AlSi3O10)(OH,O)8
9.EC.55BaileychloreZn5Al(AlSi3O10)(OH)8Tric. 1
9.EC.55SudoiteMg2Al3(AlSi3O10)(OH)8Mon. 2/m : B2/m
9.EC.55GlagoleviteNa(Mg,Al)6(AlSi3O10)(OH,O)8Tric. 1 : P1
9.EC.55DonbassiteAl4.33(AlSi3O10)(OH)8Mon. 2 : B2
9.EC.60DozyiteMg7Al2(Al2Si4O15)(OH)12Mon.
9.EC.60Rectorite(Na,Ca)Al4((Si,Al)8O20)(OH)4 · 2H2OMon.
9.EC.60Corrensite(Mg,Fe)9((Si,Al)8O20)(OH)10 · nH2OOrth.
9.EC.60AliettiteCa0.2Mg6((Si,Al)8O20)(OH)4 · 4H2OMon.
9.EC.60Karpinskite(Ni,Mg)2Si2O5(OH)2 (?)Mon.
9.EC.60LunijianlaiteLi0.7Al6.2(AlSi7O20)(OH,O)10Mon.
9.EC.60TosuditeNa0.5(Al,Mg)6((Si,Al)8O18)(OH)12 · 5H2OMon. 2 : B2
9.EC.60HydrobiotiteK(Mg,Fe2+)6((Si,Al)8O20)(OH)4 · nH2OMon. 2/m : B2/m
9.EC.60Saliotite(Li,Na)Al3(AlSi3O10)(OH)5Mon. 2/m : B2/m
9.EC.60KulkeiteMg8Al(AlSi7O20)(OH)10Mon.
9.EC.60BrinrobertsiteNa0.3Al4(Si4O10)2(OH)4 · 3.5 H2OMon.
9.EC.70BurckhardtitePb2(Fe3+Te6+)[AlSi3O8]O6Trig. 3m(32/m) : P31m
9.EC.75Niksergievite(Ba,Ca)2Al3(AlSi3O10)(CO3)(OH)6 · nH2OMon.
9.EC.75Ferrisurite(Pb,Ca)2.4Fe3+2(Si4O10)(CO3)1.7(OH)3 · nH2OMon.
9.EC.75Surite(Pb,Ca)3(Al,Fe2+,Mg)2((Si,Al)4O10)(CO3)2(OH)2Mon. 2 : P21
9.EC.80KegelitePb8Al4(Si8O20)(SO4)2(CO3)4(OH)8Mon.

Other InformationHide

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 MacaulayiteHide

References for MacaulayiteHide

Localities for MacaulayiteHide

Showing 4 localities.

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.
Hide all sections | Show all sections

Locality ListHide

- 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.
Italy
 
  • Lombardy
    • Varese Province
      • Cuasso al Monte
        • Cavagnano
Vignola et al. (2018)
Romania
 
  • Maramureș County
    • Târgu Lăpuș
HÎRTOPANU et al. (2025)
UK (TL)
 
  • Scotland
    • Aberdeenshire
      • Inverurie
Wilson et al. (1984)
USA
 
  • New Hampshire
    • Carroll County
      • Albany
        • Blue Mountain
Wayne Osborne Collection
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