Messelite Mineral Data

General Messelite Information

Chemical Formula:

Ca2(Fe++,Mn)(PO4)2•2(H2O)

Composition:

Molecular Weight = 361.75 gm

Calcium 22.16 % Ca 31.00 % CaO

Manganese 3.80 % Mn 4.90 % MnO

Iron 11.58 % Fe 14.90 % FeO

Phosphorus 17.12 % P 39.24 % P₂O₅

Hydrogen 1.11 % H 9.96 % H₂O

Oxygen 44.23 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂Fe²⁺_0.75Mn²⁺_0.25(PO₄)₂•2(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1889

Locality:

Messel, Germany. Link to MinDat.org Location Data.

Name Origin:

Named after its locality.

Name Pronunciation:

Messelite + Pronunciation

Messelite Image

Images:

Messelite Leucophosphite

Comments: White messelite crystals with greenish leucophosphite.
Location: Tip Top mine, Custer, Custer County, South Dakota, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Messelite Crystallography

Axial Ratios:

a:b:c =0.8787:1:0.8333

Cell Dimensions:

a = 5.8, b = 6.6, c = 5.5, Z = 1; alpha = 102°, beta = 109°, gamma = 90° V = 194.72 Den(Calc)= 3.08

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 3.17(1), 6.34(1), 3.02(0.8),

Physical Properties of Messelite

Cleavage:

{001} Good, {010} Distinct

Color:

Colorless, Greenish white, Gray, Gray white, White.

Density:

3 - 3.16, Average = 3.08

Diaphaneity:

Transparent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Habit:

Scaly - Morphology like fish scales.

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

3.5 - Copper Penny

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Messelite

Gladstone-Dale:

CI meas= -0.026 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.023 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2133,KPDmeas= 0.214,KC= 0.2084
Ncalc = 1.63 - 1.66

Optical Data:

Biaxial (+), a=1.644, b=1.653, g=1.68, bire=0.0360, 2V(Calc)=62, 2V(Meas)=20-35.

Calculated Properties of Messelite

Electron Density:

Bulk Density (Electron Density)=3.07 gm/cc
note: Specific Gravity of Messelite =3.09 gm/cc.

Fermion Index:

Fermion Index = 0.0029677474
Boson Index = 0.9970322526

Photoelectric:

PE_Messelite= 7.90 barns/electron
U=PE_Messelite x rElectron Density= 24.27 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Messelite is Not Radioactive

Messelite Classification

Dana Class:

40.02.02.02 (40)Hydrated Phosphates, etc

(40.02)where A++ (B++)2 (XO4) ï¿½ x(H2O)

(40.02.02)Fairfieldite Subgroup (Triclinic: P-1ï¿½)

40.02.02.01 Fairfieldite Ca2(Mn,Fe)(PO4)2•2(H2O) P1 1

40.02.02.02 Messelite Ca2(Fe,Mn)(PO4)2•2(H2O) P1 1

40.02.02.03 Collinsite Ca2(Mg,Fe)(PO4)2•2(H2O) P1 1

40.02.02.04 Cassidyite Ca2(Ni,Mg)(PO4)2•2(H2O) P1 1

40.02.02.05 Talmessite Ca2Mg(AsO4)2•2(H2O) P1 1

40.02.02.06 Gaitite Ca2Zn(AsO4)2•2(H2O) P1 1

40.02.02.07 Roselite-beta Ca2(Co,Mg)(AsO4)2•2(H2O) P 1 or P1 Tri

40.02.02.08 Parabrandtite Ca2Mn(AsO4)•2(H2O) P1,P 1 Tri

40.02.02.09 Hillite! Ca2(Zn,Mg)[PO4]2•2(H2O) P1 1

40.02.02.10 Nickeltalmessite! Ca2Ni(AsO4)2•2H2O P 1

Strunz Class:

08.CG.05 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CG -With large and medium-sized cations, RO4:H2O = 1:1

08.CG.05 Collinsite Ca2(Mg,Fe)(PO4)2•2(H2O) P1 1

08.CG.05 Gaitite Ca2Zn(AsO4)2•2(H2O) P1 1

08.CG.05 Cassidyite Ca2(Ni,Mg)(PO4)2•2(H2O) P1 1

08.CG.05 Fairfieldite Ca2(Mn,Fe)(PO4)2•2(H2O) P1 1

08.CG.05 Messelite Ca2(Fe,Mn)(PO4)2•2(H2O) P1 1

08.CG.05 Parabrandtite Ca2Mn(AsO4)•2(H2O) P1,P 1 Tri

08.CG.05 Uranophane-beta Ca[(UO2)SiO3(OH)]2•(H2O) P 2₁/a 2/m

08.CG.05 Talmessite Ca2Mg(AsO4)2•2(H2O) P1 1

08.CG.05 Hillite! Ca2(Zn,Mg)[PO4]2•2(H2O) P1 1

Other Messelite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Messelite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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

Messelite

Ca2(Fe++,Mn)(PO4)2•2(H2O)
Dana No: 40.02.02.02 Strunz No: 08.CG.05
Locality:

Notes:

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