Jahnsite-(CaMnMg) Mineral Data (original) (raw)

General Jahnsite-(CaMnMg) Information

Help on Chemical Formula: Chemical Formula:

CaMnMg2Fe+++2(PO4)4(OH)2•8(H2O)

Help on Composition: Composition:

Molecular Weight = 813.34 gm

Calcium 4.93 % Ca 6.89 % CaO

Magnesium 5.98 % Mg 9.91 % MgO

Manganese 6.75 % Mn 8.72 % MnO

Iron 13.73 % Fe 19.63 % Fe2O3

Phosphorus 15.23 % P 34.90 % P2O5

Hydrogen 2.23 % H 19.93 % H2O

Oxygen 51.15 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Help on Empirical Formula: Empirical Formula:

CaMn2+Mg2Fe3+2(PO4)4(OH)2•8(H2O)

Help on IMA Status: IMA Status:

Approved IMA 1974

Help on Locality: Locality:

Tip Top pegmatite, Custer, South Dakota, USA. Link to MinDat.org Location Data.

Help on Name Origin: Name Origin:

Named for Richard H. Jahns (1915-1983), mineralogist and pegmatite expert, Stanford University, Palo Alto, California, USA.

Help on Name Pronunciation: Name Pronunciation:

Jahnsite-(CaMnMg) Say JAHNSITE-(CAMNMG)

Help on Synonym: Synonym:

Jahnsite

Jahnsite-(CaMnMg) Image

Click Here for Larger Jahnsite-(CaMnMg) Image in a New Browser Window Images:

Jahnsite-(CaMnMg) Crystallography

Help on Axial Ratios: Axial Ratios:

a:b:c =2.0924:1:1.3907

Help on Cell Dimensions: Cell Dimensions:

a = 14.94, b = 7.14, c = 9.93, Z = 2; beta = 110.68° V = 991.00 Den(Calc)= 2.73

Help on Crystal System: Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2/a

Help on X Ray Diffraction: X Ray Diffraction:

By Intensity(I/Io): 9.27(1), 2.825(0.8), 4.91(0.6),

Click Here for Large Jahnsite-(CaMnMg) Structure Window Crystal Structure:

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Help on Above

| | Moore P B , Araki T , American Mineralogist , 59 (1974) p.964-973, Jahnsite, CaMnMg2(H2O)8Fe2(OH)2[PO4]4: A novel stereoisomerism of, ligands about octahedral corner-chains | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

Physical Properties of Jahnsite-(CaMnMg)

Help on Cleavage: Cleavage:

{001} Good

Help on Color: Color:

Brown, Purplish brown, Yellow, Yellow orange, Greenish yellow.

Help on Density: Density:

2.706 - 2.718, Average = 2.71

Help on Diaphaneity: Diaphaneity:

Transparent to Translucent

Help on Fracture: Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Help on Hardness: Hardness:

4 - Fluorite

Help on Luster: Luster:

Vitreous - Adamantine

Help on Streak: Streak:

white

Optical Properties of Jahnsite-(CaMnMg)

Help on Gladstone-Dale: Gladstone-Dale:

CI meas= 0.013 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.019 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2403,KPDmeas= 0.2419,KC= 0.245
Ncalc = 1.66 - 1.67

Help on Optical Data: Optical Data:

Biaxial (+), a=1.64, b=1.658, g=1.67, bire=0.0300

Help on Pleochroism (x): Pleochroism (x):

pale purple.

Help on Pleochroism (y): Pleochroism (y):

deep purplish brown.

Help on Pleochroism (z): Pleochroism (z):

greenish yellow.

Calculated Properties of Jahnsite-(CaMnMg)

Help on Electron Density: Electron Density:

Bulk Density (Electron Density)=2.71 gm/cc
note: Specific Gravity of Jahnsite-(CaMnMg) =2.71 gm/cc.

Help on Fermion Index: Fermion Index:

Fermion Index = 0.0092032727
Boson Index = 0.9907967273

Help on Photoelectric: Photoelectric:

PEJahnsite-(CaMnMg) = 7.19 barns/electron
U=PEJahnsite-(CaMnMg) x rElectron Density= 19.50 barns/cc.

Help on Radioactivity: Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Jahnsite-(CaMnMg) is Not Radioactive

Jahnsite-(CaMnMg) Classification

Help on Dana Class: Dana Class:

42.11.02.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.11)where (AB)4 (XO4)3 Zq � x(H2O)

(42.11.02)Jahnsite Group

42.11.02.01 Jahnsite-(CaMnMg) CaMnMg2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

42.11.02.02 Jahnsite-(CaMnFe) CaMnFe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

42.11.02.03 Jahnsite-(CaMnMn) CaMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

42.11.02.04 Jahnsite-(MnMnMn)* MnMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

Help on Strunz Class: Strunz Class:

08.DH.15 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DH -With large and medium-sized cations, (OH, etc.):RO4 < 1:1

08.DH.15 Keckite Ca(Mn,Zn)2Fe3(PO4)4(OH)3•2(H2O) P 21/a 2/m

08.DH.15 Jahnsite-(CaMnFe) CaMnFe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(CaMnMg) CaMnMg2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(CaMnMn) CaMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(MnMnMn)* MnMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Kaluginite* (Mn,Ca)MgFe(PO4)2(OH)•4(H2O) C cca 2/m 2/m 2/m

08.DH.15 Rittmannite MnMnFeAl2(OH)2(PO4)4•8(H2O) P 2/a 2/m

08.DH.15 Whiteite-(MnFeMg) (Mn,Ca)(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Whiteite-(CaFeMg) Ca(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 21/a 2/m

08.DH.15 Whiteite-(CaMnMg) CaMnMg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(CaFeFe)! (Ca,Mn)(Fe,Mn)Fe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(NaFeMg)! NaFeMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

08.DH.15 Jahnsite-(CaMgMg)! CaMgMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

08.DH.15 Jahnsite-(NaMnMg)! NaMnMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

Other Jahnsite-(CaMnMg) Information

Help on References: References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

Help on See Also: See Also:

Links to other databases for Jahnsite-(CaMnMg) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info
11 - WWW-MINCRYST

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Print or Cut-and-Paste your Jahnsite-(CaMnMg) Specimen Label here :

Jahnsite-(CaMnMg)

CaMnMg2Fe+++2(PO4)4(OH)2•8(H2O)
Dana No: 42.11.02.01 Strunz No: 08.DH.15
Locality:

Notes: