Cafetite Mineral Data
General Cafetite Information
Chemical Formula:
Ca(Fe,Al)2Ti4O12•4(H2O)
Composition:
Molecular Weight = 592.91 gm
Calcium 6.76 % Ca 9.46 % CaO
Titanium 32.30 % Ti 53.89 % TiO2
Aluminum 2.28 % Al 4.30 % Al2 O3
Iron 14.13 % Fe 18.18 % FeO
Hydrogen 1.36 % H 12.15 % H2 O
Oxygen 43.18 % O
______ ______
100.00 % 97.98 % = TOTAL OXIDE
Empirical Formula:
CaFe2+ 1.5 Al0.5 Ti4 O12 •4(H2 O)
Environment:
In miarolitic cavities in pegmatites cutting pyroxenite. Later work suggests that Fe was a contaminent from magnetite and not an essential part of the formula.
IMA Status:
Approved IMA 1959
Locality:
Afrikanda massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.
Name Origin:
Named for the composition (Ca, Fe, Ti).
Name Pronunciation:
Cafetite
Cafetite Image
Images:
Cafetite Crystallography
Axial Ratios:
a:b:c =0.4084:1:1.3139
Cell Dimensions:
a = 4.9463, b = 12.109, c = 15.911, Z = 3; beta = 98.937° V = 941.42 Den(Calc)= 3.14
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /n
X Ray Diffraction:
By Intensity(I/Io ): 7.86(1), 2.56(0.8), 1.91(0.7),
Physical Properties of Cafetite
Cleavage:
{???} Good
Color:
Colorless, Pale yellow.
Density:
3.28
Diaphaneity:
Transparent
Fracture:
Brittle - Generally displayed by glasses and most non-metallic minerals.
Habit:
Acicular - Occurs as needle-like crystals.
Habit:
Aggregates - Made of numerous individual crystals or clusters.
Habit:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Hardness:
4-5 - Fluorite-Apatite
Luster:
Adamantine
Streak:
white
Optical Properties of Cafetite
Gladstone-Dale:
CI meas = -0.01 (Superior) - where the CI = (1-KPDmeas /KC ) CI calc = -0.055 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.3333,KPDmeas = 0.3191,KC = 0.316 Ncalc = 1.99 - 2.04
Optical Data:
Biaxial (-), a=1.95, b=2.08, g=2.11, bire=0.1600, 2V(Calc)=48, 2V(Meas)=38.
Calculated Properties of Cafetite
Electron Density:
Bulk Density (Electron Density)=3.20 gm/cc note: Specific Gravity of Cafetite =3.28 gm/cc.
Fermion Index:
Fermion Index = 0.04 Boson Index = 0.96
Photoelectric:
PECafetite = 10.44 barns/electronU=PECafetite x r Electron Density= 33.44 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Cafetite is Not Radioactive
Cafetite Classification
Dana Class:
08.07.03.01 (08) Multiple Oxides with Nb, Ta, and Ti
(08.07) Dana Type
(08.07.03) Dana Group
08.07.03.01 Cafetite Ca(Fe,Al)2Ti4O12•4(H2O) P 21 /n 2/m
Strunz Class:
04.FL.75 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
04.F - Hydroxides (without V or U)
04.FL -Hydroxides with H2O � (OH); sheets of edge-sharing octahedra
04.FL.75 Cafetite Ca(Fe,Al)2Ti4O12•4(H2O) P 21 /n 2/m
Other Cafetite Information
References:
NAME( Dana8) PHYS. PROP.(AmMin, Vol 88, p 424) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Cafetite :
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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Cafetite
Ca(Fe,Al)2Ti4O12•4(H2O)
Dana No: 08.07.03.01 Strunz No: 04.FL.75
Locality:
Notes:
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