Cacoxenite Mineral Data

General Cacoxenite Information

Chemical Formula:

(Fe+++,Al)25(PO4)17O6(OH)12•75(H2O)

Composition:

Molecular Weight = 4,481.51 gm

Aluminum 3.76 % Al 7.11 % Al₂O₃

Iron 23.37 % Fe 30.06 % FeO

Phosphorus 11.75 % P 26.92 % P₂O₅

Hydrogen 3.64 % H 32.56 % H₂O

Oxygen 57.48 % O

______ ______

100.00 % 96.65 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺_18.75Al_6.25(PO₄)₁₇O₆(OH)₁₂•75(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1825

Locality:

Link to MinDat.org Location Data.

Name Origin:

From the Greek kakos, meaning "wrong" and xenos, meaning "guest.;"

Name Pronunciation:

Cacoxenite + Pronunciation

Synonym:

ICSD 30834

Kakoxen

PDF 14-331

Cacoxenite Image

Images:

Cacoxenite

Comments: Radial, spherical individual crystal sprays of brownish yellow cacoxenite.
Location: El Horcajo (Ciudad Real), Spain. Scale: 0.5 mm diameter.
© Tom Loomis / Dakota Matrix

Images:

Strengite Cacoxenite

Comments: Lilac colored, spear-head shape crystals of strengite to 5mm in large, open vug associated with golden fibrous cacoxenite.
Location: Coon Creek, Polk Co., Arkansas, USA. Scale: Picture size 2 cm.
© Tom Loomis / Dakota Matrix

Cacoxenite Crystallography

Axial Ratios:

a:c = 1:0.38662

Cell Dimensions:

a = 27.559, c = 10.655, Z = 3; V = 7,008.27 Den(Calc)= 3.19

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6/mmm

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

By Intensity(I/I_o): 11.9(1), 23.1(1), 9.1(0.14),

Physical Properties of Cacoxenite

Cleavage:

None

Color:

Brownish yellow, Green, Yellow, Golden yellow, Red yellow.

Density:

2.3 - 3.4, Average = 2.84

Fracture:

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

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

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

Habit:

Stellate - Occurs as spherical, radial aggregates radiating from a "star" like point.

Hardness:

3-3.5 - Calcite-Copper Penny

Luminescence:

Non-fluorescent.

Luster:

Silky

Streak:

yellow

Optical Properties of Cacoxenite

Dichroism (e):

non.

Gladstone-Dale:

CI meas= 0.069 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.168 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1924,KPDmeas= 0.2154,KC= 0.2312
Ncalc = 1.53 - 1.79

Optical Data:

Uniaxial (+), w=1.58-1.585, e=1.64-1.65, bire=0.0600-0.0650.

Calculated Properties of Cacoxenite

Electron Density:

Bulk Density (Electron Density)=2.89 gm/cc
note: Specific Gravity of Cacoxenite =2.85 gm/cc.

Fermion Index:

Fermion Index = 0.0052348676
Boson Index = 0.9947651324

Photoelectric:

PE_Cacoxenite= 7.48 barns/electron
U=PE_Cacoxenite x rElectron Density= 21.63 barns/cc.

Radioactivity:

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

Cacoxenite Classification

Dana Class:

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

(42.13)Dana Type

(42.13.05)Dana Group

42.13.05.01 Cacoxenite (Fe,Al)25(PO4)17O6(OH)12•75(H2O) P 6/mmm 6/m 2/m 2/m

Strunz Class:

08.DC.40 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DC -With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1

08.DC.40 Cacoxenite (Fe,Al)25(PO4)17O6(OH)12•75(H2O) P 6/mmm 6/m 2/m 2/m

Other Cacoxenite Information

References:

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

See Also:

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

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

Cacoxenite

(Fe+++,Al)25(PO4)17O6(OH)12•75(H2O)
Dana No: 42.13.05.01 Strunz No: 08.DC.40
Locality:

Notes:

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