Gerstmannite Mineral Data

Gerstmannite Mineral Data +

[Mineral Specimens] [Our best] [Rare specimens] [Latest updates] [Home Page]
Fine Minerals, Moldavites, Jewellery, Meteorites and Fossils
Rockshop.cz is based in Prague, Czech republic

General Gerstmannite Information

Chemical Formula:

(Mg,Mn)2ZnSiO4(OH)2

Composition:

Molecular Weight = 255.41 gm

Magnesium 14.27 % Mg 23.67 % MgO

Manganese 10.75 % Mn 13.89 % MnO

Zinc 25.60 % Zn 31.87 % ZnO

Silicon 11.00 % Si 23.52 % SiO₂

Hydrogen 0.79 % H 7.05 % H₂O

Oxygen 37.58 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_1.5Mn²⁺_0.5Zn(SiO₄)(OH)₂

IMA Status:

Approved IMA 1977

Locality:

Link to MinDat.org Location Data.

Synonym:

ICSD 100142

PDF 29-867

Search for Gerstmannite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Gerstmannite Crystallography

Axial Ratios:

a:b:c =0.4388:1:0.3351

Cell Dimensions:

a = 8.185, b = 18.65, c = 6.25, Z = 8; V = 954.06 Den(Calc)= 3.56

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Bbam

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.598(1), 9.326(0.85), 3.418(0.8),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Moore P B , Araki T , American Mineralogist , 62 (1977) p.51-59, Gerstmannite, a new zinc silicate mineral and a novel cubic close-packed oxide, structure

Physical Properties of Gerstmannite

Cleavage:

[010] Good

Color:

White, Light pink.

Density:

3.68

Diaphaniety:

Translucent to Opaque

Hardness:

4.5 - Between Fluorite and Apatite

Luster:

Vitreous - Adamantine

Streak:

white

Optical Properties of Gerstmannite

Gladstone-Dale:

CI meas= 0.089 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.059 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1863,KPDmeas= 0.1803,KC= 0.198

Optical Data:

Biaxial (-), a=1.655, b=1.657, g=1.678, bire=0.0230, 2V(Calc)=36, 2V(Meas)=50-60.

Calculated Properties of Gerstmannite

Electron Density:

r_electron=3.47 gm/cc
note: r_Gerstmannite=3.56 gm/cc.

Fermion Index

Fermion Index = 0.03008
Boson Index = 0.96992

Photoelectric:

PE_Gerstmannite= 16.05 barns/electron
U=PE_Gerstmannite x r_electron= 55.70 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Gerstmannite is Not Radioactive

Gerstmannite Classification

Dana Class:

52.2.1.4 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.2)with cations in [4] and >[4] coordination

(52.2.1)Euclase group

52.2.1.1 Euclase BeAlSiO4(OH) P 2₁/a 2/m

52.2.1.2 Clinohedrite CaZnSiO4·(H2O) Aa m

52.2.1.3. Hodgkinsonite MnZn2SiO4(OH)2 P 2₁/c 2/m

52.2.1.4 Gerstmannite (Mg,Mn)2ZnSiO4(OH)2 Bbam 2/m 2/m 2/m

Strunz Class:

VIII/B.03-20 VIII - Silicates

VIII/B - Nesosubsilicates, with anions unfamiliar to tetraheders, cations of octahedral and tetrahedral orientation [4/6]

VIII/B.03 - Staurolite - Gerstmannite series

VIII/B.03-03 Magnesiostaurolite! []4Mg4Al16(Al,[])2Si8O40[O6,(OH)2] C 2/m 2/m

VIII/B.03-05 Zincostaurolite! []4Zn4Al16(Al,[])2Si8O40[O6,(OH)2] C 2/m 2/m

VIII/B.03-10 Staurolite (Fe,Mg)2Al9(Si,Al)4O20(O,OH)4 C 2/m 2/m

VIII/B.03-20 Gerstmannite (Mg,Mn)2ZnSiO4(OH)2 Bbam 2/m 2/m 2/m

Other Gerstmannite Information

References:

PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

Search for Gerstmannite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Gerstmannite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Gerstmannite Mineral Data :

Ask about Gerstmannite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Gerstmannite Specimen Label here :

Gerstmannite

(Mg,Mn)2ZnSiO4(OH)2
Dana No: 52.2.1.4 Strunz No: VIII/B.03-20
Locality:

Notes: