Gerstmannite
This page is currently not sponsored. Click here to sponsor this page.
About Gerstmannite
Ewald Gerstmann
Formula:
MnMgZn(SiO4)(OH)2
Hardness:
4½
Crystal System:
Orthorhombic
Name:
Named in 1977 by Paul Brian Moore and Takaharu Araki after Mr. Ewald "The Dutchman" Gerstmann [September 19, 1918 in Bremerhaven, Germany - December 14, 2005, Andover, New Jersey], stationary engineer, mineral dealer, and avid collector of Franklin Mining District minerals. Operator of a private mineral museum and collectors' gathering spot at Franklin, NJ, for many years. The Gerstmann mineral collection was donated to the Franklin Mineral Museum.
This page provides mineralogical data about Gerstmannite.
Classification of Gerstmannite
Approved
Approval Year:
1975
8/B.03-20
9.AE.25
9 : SILICATES (Germanates)
A : Nesosilicates
E : Nesosilicates with additional anions (O,OH,F,H2O); cations in tetrahedral [4] coordination
9 : SILICATES (Germanates)
A : Nesosilicates
E : Nesosilicates with additional anions (O,OH,F,H2O); cations in tetrahedral [4] coordination
52.2.1.4
52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
2 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [4] and >[4] coordination
52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
2 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [4] and >[4] coordination
14.7.21
14 : Silicates not Containing Aluminum
7 : Silicates of Ba, Sr and Zn
14 : Silicates not Containing Aluminum
7 : Silicates of Ba, Sr and Zn
Physical Properties of Gerstmannite
Hardness:
4½ on Mohs scale
Optical Data of Gerstmannite
Type:
Biaxial (-)
RI values:
nα = 1.655 nβ = 1.657 nγ = 1.678
2V:
Measured: 50° to 60°, Calculated: 36°
Max Birefringence:
δ = 0.023
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
weak
Chemical Properties of Gerstmannite
Formula:
MnMgZn(SiO4)(OH)2
IMA Formula:
Mn2+MgZn(SiO4)(OH)2
Common Impurities:
Fe,Na
Crystallography of Gerstmannite
Crystal System:
Orthorhombic
Cell Parameters:
a = 8.18 Å, b = 18.65 Å, c = 6.25 Å
Ratio:
a:b:c = 0.439 : 1 : 0.335
Unit Cell V:
953.48 ų (Calculated from Unit Cell)
Type Occurrence of Gerstmannite
Synonyms of Gerstmannite
Other Language Names for Gerstmannite
Related Minerals - Nickel-Strunz Grouping
| 9.AE.05 | Beryllite | Be3(SiO4)(OH)2 · H2O | Orth. |
| 9.AE.10 | Euclase | BeAl(SiO4)(OH) | Mon. 2/m : P21/b |
| 9.AE.15 | Sverigeite | NaMnMgSnBe2(SiO4)3(OH) | Orth. mmm (2/m 2/m 2/m) : Imma |
| 9.AE.20 | Hodgkinsonite | Mn2+Zn2(SiO4)(OH)2 | Mon. |
| 9.AE.30 | Clinohedrite | CaZn(SiO4) · H2O | Mon. m : Bb |
| 9.AE.35 | Stringhamite | CaCu(SiO4) · H2O | Mon. |
| 9.AE.40 | Katoptrite | (Mn2+,Mg)13(Al,Fe3+)4Sb5+2(SiO4)2O20 | Mon. 2/m : B2/m |
| 9.AE.45 | Yeatmanite | Zn6Mn2+9Sb5+2(SiO4)4O12 | Tric. |
| 9.AE.50 | Sphaerobertrandite | Be3(SiO4)(OH)2 | Mon. 2/m : P21/b |
Related Minerals - Dana Grouping (8th Ed.)
| 52.2.1.1 | Euclase | BeAl(SiO4)(OH) | Mon. 2/m : P21/b |
| 52.2.1.2 | Clinohedrite | CaZn(SiO4) · H2O | Mon. m : Bb |
| 52.2.1.3 | Hodgkinsonite | Mn2+Zn2(SiO4)(OH)2 | Mon. |
Related Minerals - Hey's Chemical Index of Minerals Grouping
| 14.7.1 | Sanbornite | Ba2(Si4O10) | Orth. |
| 14.7.2 | Krauskopfite | BaSi2O5 · 3H2O | Mon. |
| 14.7.3 | Walstromite | BaCa2(Si3O9) | Tric. |
| 14.7.4 | Macdonaldite | BaCa4Si16O36(OH)2 · 10H2O | Orth. |
| 14.7.5 | Ericssonite | BaMn2+2Fe3+(Si2O7)O(OH) | Mon. 2/m : B2/m |
| 14.7.6 | Ericssonite-2O | BaMn2+2Fe3+(Si2O7)O(OH) | Orth. |
| 14.7.7 | Gillespite | BaFe2+Si4O10 | Tet. |
| 14.7.8 | Andrémeyerite | BaFe2+2(Si2O7) | Mon. |
| 14.7.9 | Pellyite | Ba2Ca(Fe,Mg)2Si6O17 | Orth. |
| 14.7.10 | Taikanite | Sr3BaMn2+2(Si4O12)O2 | Mon. |
| 14.7.11 | Willemite | Zn2SiO4 | Trig. 3 : R3 |
| 14.7.12 | Hemimorphite | Zn4Si2O7(OH)2 · H2O | Orth. mm2 : Imm2 |
| 14.7.13 | Zincsilite | Zn3(Si4O10)(OH)2 · 4H2O | Mon. |
| 14.7.14 | Hardystonite | Ca2Zn(Si2O7) | Tet. 4 2m : P4 21m |
| 14.7.15 | Petedunnite | Ca(Zn,Mn2+,Mg,Fe2+)Si2O6 | Mon. |
| 14.7.16 | Clinohedrite | CaZn(SiO4) · H2O | Mon. m : Bb |
| 14.7.17 | Junitoite | CaZn2Si2O7 · H2O | Orth. mm2 |
| 14.7.18 | Larsenite | PbZnSiO4 | Orth. mm2 : Pna21 |
| 14.7.19 | Esperite | PbCa2Zn3(SiO4)3 | Mon. 2/m : P21/b |
| 14.7.20 | Hodgkinsonite | Mn2+Zn2(SiO4)(OH)2 | Mon. |
| 14.7.22 | Gageite | Mn21(Si4O12)2O3(OH)20 | Mon. 2/m |
| 14.7.23 | Franklinfurnaceite | Ca2Fe3+Mn2+3Mn3+(Zn2Si2O10)(OH)8 | Mon. 2 : B2 |
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 Gerstmannite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
American Mineralogist: 51-59.
Internet Links for Gerstmannite
mindat.org URL:
https://www.mindat.org/min-1685.html
Please feel free to link to this page.
Please feel free to link to this page.
External Links:
Mineral Dealers:
Localities for Gerstmannite
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for 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.
USA (TL) | |
| Moore, P.B. & Araki, T.: Am.Min.:62:51-59 (1977); Dunn(1995):Pt3:369. |
Sterling Mine, Sterling Hill, Ogdensburg, Franklin mining district, Sussex Co., New Jersey, USA