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 % P2 O5
Hydrogen 1.11 % H 9.96 % H2 O
Oxygen 44.23 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Ca2 Fe2+ 0.75 Mn2+ 0.25 (PO4 )2 •2(H2 O)
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 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
X Ray Diffraction:
By Intensity(I/Io ): 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:
PEMesselite = 7.90 barns/electronU=PEMesselite x r Electron 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) � x(H2O)
(40.02.02) Fairfieldite Subgroup (Triclinic: P-1�)
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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