Akatoreite
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Formula:
Mn92+Al2Si8O24(OH)8
System:
Triclinic
Colour:
Yellow-orange to ...
Lustre:
Vitreous
Hardness:
6
Name:
Named after its discovery locality at Akatore in New Zealand.
Classification of Akatoreite
Approved
Approval Year:
1969
8/C.35-20
9.BH.15
9 : SILICATES (Germanates)
B : Sorosilicates
H : Sorosilicates with Si3O10, Si4O11, etc. anions; cations in tetrahedral [4] and greater coordination
9 : SILICATES (Germanates)
B : Sorosilicates
H : Sorosilicates with Si3O10, Si4O11, etc. anions; cations in tetrahedral [4] and greater coordination
57.2.3.1
57 : SOROSILICATES Si3O10 Groups and Larger Noncyclic Groups
2 : Insular Si3O10 and Larger Noncyclic Groups with [Si4O13] groups
57 : SOROSILICATES Si3O10 Groups and Larger Noncyclic Groups
2 : Insular Si3O10 and Larger Noncyclic Groups with [Si4O13] groups
16.16.8
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
Physical Properties of Akatoreite
Vitreous
Diaphaneity (Transparency):
Transparent
Colour:
Yellow-orange to orange-brown
Streak:
yellowish white
Hardness (Mohs):
6
Cleavage:
Perfect
Good on {010} , poor on {0_12}
Good on {010} , poor on {0_12}
Optical Data of Akatoreite
Type:
Biaxial (+)
RI values:
nα = 1.698 nβ = 1.704 nγ = 1.720
2V:
Measured: 65° , Calculated: 64°
Max Birefringence:
δ = 0.022
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
High
Dispersion:
relatively strong
Chemical Properties of Akatoreite
Formula:
Mn92+Al2Si8O24(OH)8
Common Impurities:
Ti,Fe,Mg,Ca
Crystallography of Akatoreite
Crystal System:
Triclinic
Cell Parameters:
a = 8.33 Å, b = 10.36 Å, c = 7.62 Å
α = 104.46°, β = 93.81°, γ = 104.18°
α = 104.46°, β = 93.81°, γ = 104.18°
Ratio:
a:b:c = 0.804 : 1 : 0.736
Unit Cell Volume:
V 611.63 ų (Calculated from Unit Cell)
Morphology:
Rarely as sheaves, to 1 cm, of radiating prisms, elongated and striated parallel[100] ; fibrous, fine granular, massive.
Twinning:
Twinning: On {021} twin axis perpindicular
{021}, lamellar in thin section.
{021}, lamellar in thin section.
Occurrences of Akatoreite
Type Occurrence of Akatoreite
Place of Conservation of Type Material:
University of Otago, Dunedin; Geological Survey of New Zealand, Lower Hutt, New Zealand; National Museum of Natural History, Washington, D.C., USA, 137285, 142541.
Geological Setting of Type Material:
In a manganiferous metachert and carbonate lens in schists
Associated Minerals at Type Locality:
Relationship of Akatoreite to other Species
Common Associates:
| 9.BH.05 | Aminoffite | Ca3(BeOH)2Si3O10 |
| 9.BH.10 | Kinoite | Ca2Cu2Si3O10 · 2H2O |
| 9.BH.20 | Fencooperite | Ba6Fe33+Si8O23(CO3)2Cl3 · H2O |
| 16.16.1 | Kanonaite | Mn3+AlOSiO4 |
| 16.16.2 | Spessartine | Mn32+Al2(SiO4)3 |
| 16.16.3 | Davreuxite | Mn2+Al6Si4O17(OH)2 |
| 16.16.4 | Sursassite | Mn22+Al3(SiO4)(Si2O7)(OH)3 |
| 16.16.5 | Carpholite | Mn2+Al2Si2O6(OH)4 |
| 16.16.6 | Kellyite | (Mn2+,Mg,Al)3(Si,Al)2O5(OH)4 |
| 16.16.7 | Pennantite | (Mn2+,Al)6(Si,Al)4O10(OH)8 |
| 16.16.9 | Ganophyllite | (K,Na)xMn62+(Si,Al)10O24(OH)4 · nH2O (x=1-2; n=7-11) |
| 16.16.10 | Mangano-ferri-eckermannite | NaNa2(Mn42+Fe3+)Si8O22(OH)2 |
| 16.16.11 | Masutomilite | KLiAlMn2+(Si3Al)O10(F,OH)2 |
| 16.16.13 | Howieite | Na(Fe2+,Fe3+,Al,Mg)12(Si6O17)2(O,OH)10 |
| 16.16.14 | Eggletonite | (Na,K,Ca)xMn6(Si,Al)10O24(OH)4 · nH2O, (x = 1-2, n = 7-11) |
| 16.16.15 | Bannisterite | (Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2O |
| 16.16.16 | Taneyamalite | (Na,Ca)Mn122+(Si,Al)12(O,OH)44 |
| 16.16.17 | Zussmanite | K(Fe,Mg,Mn)13(Si,Al)18O42(OH)14 |
| 16.16.18 | Coombsite | KMn132+Si18O42(OH)15 |
| 16.16.19 | Henritermierite | Ca3Mn23+(SiO4)2(OH)4 |
| 16.16.20 | Macfallite | Ca2Mn33+(SiO4)(Si2O7)(OH)3 |
| 16.16.21 | Ottrélite | Mn2+Al2O(SiO4)(OH)2 |
| 16.16.22 | Piemontite | Ca2Mn3+Al2(Si2O7)(SiO4)O(OH) |
| 16.16.23 | Okhotskite | Ca2(Mn,Mg)(Mn3+,Al,Fe3+)2Si3(O,OH)14 |
| 16.16.24 | Pumpellyite-(Mn2+) | Ca2Mn2+Al2(SiO4)(Si2O7)(OH)2 · H2O |
| 16.16.25 | Piemontite-(Sr) | CaSrMn3+Al2(Si2O7)(SiO4)O(OH) |
Other Names for Akatoreite
Name in Other Languages:
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.
References for Akatoreite
Reference List:
Read, P.B., Reay, A. (1971) Akatoreite, a new manganese silicate from eastern Otago, New Zealand. American Mineralogist; 56: 416-426.
Jambor, J.L., Grew, E.S. (1994) New mineral names. American Mineralogist: 79: 185-189.
Burns, P.C., Hawthorne, F.C. (1993) Edge–sharing Mn2+O4 tetrahedra in the structure of akatoreite, Mn2+9Al2Si8O24(OH)8. The Canadian Mineralogist: 31: 321-329.
Jambor, J.L., Grew, E.S. (1994) New mineral names. American Mineralogist: 79: 185-189.
Burns, P.C., Hawthorne, F.C. (1993) Edge–sharing Mn2+O4 tetrahedra in the structure of akatoreite, Mn2+9Al2Si8O24(OH)8. The Canadian Mineralogist: 31: 321-329.
Internet Links for Akatoreite
mindat.org URL:
https://www.mindat.org/min-68.html
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Localities for Akatoreite
This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the 
symbol to view information about a locality.
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(TL) indicates type locality for a valid mineral species. (FRL) indicates first recorded locality for everything else. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
Italy | |
| Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007): Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp. [SXRD analysis by Uwe Kolitsch] |
Japan | |
| The Mineral Species of Japan (5th ed) Matsubara; Nishio-Hamane, D., Momma, K., Miyawaki, R., Minakawa, T. (2016): Bunnoite, a new hydrous manganese aluminosilicate from Kamo Mountain, Kochi prefecture, Japan. Mineralogy and Petrology 110, 917-926. |
New Zealand (TL) | |
| Amer. Mineral. (1971) 56, 416-426; Railton, G.L. & Watters, W.A., Minerals of New Zealand, New Zealand Geological Survey Bull. #104 (1990). |
Sweden | |
| Ounchanum, P. & Morad, S. (1987): Paragenesis of akatoreite and ganophyllite in the manganiferous rocks of the Häste Field, Norberg ore district, central Sweden. Neues Jahrbuch für Mineralogie, Abhandlungen 157, 225-244. |
Maniglia Mt., Bellino, Varaita Valley, Cuneo Province, Piedmont, Italy