Cafarsite Mineral Data

[Content and History] [Recent Issues] [Back Issues] [Subscriptions] [Contacts]
See Also: [Diamond Crystals] [Excalibur Minerals] [Hudson Institute] [Minerals on CDROM]
Mineral News was founded some twenty years ago and has developed a following of
avid mineral collectors seeking timely information about new finds and other items
of interest to the collector community. Articles are solicited from collector and scientific authors.

General Cafarsite Information

Chemical Formula:

Ca8(Ti,Fe++,Fe+++,Mn)6-7(As+++O3)12•4(H2O)

Composition:

Molecular Weight = 2,230.31 gm

Calcium 14.38 % Ca 20.11 % CaO

Titanium 7.51 % Ti 12.54 % TiO₂

Manganese 1.23 % Mn 1.59 % MnO

Iron 7.51 % Fe 6.44 % FeO / 3.58 % Fe₂O₃

Arsenic 40.31 % As 53.22 % As₂O₃

Hydrogen 0.36 % H 3.23 % H₂O

Oxygen 28.69 % O

______ ______

100.00 % 100.72 % = TOTAL OXIDE

Empirical Formula:

Ca₈Ti_3.5Fe²⁺₂Fe³⁺Mn²⁺_0.5(AsO₃)₁₂•4(H₂O)

Environment:

On cleft faces in orthogneiss.

IMA Status:

Approved IMA 1966

Locality:

West flank of Cherbadung [Pizzo Cervandone], Binntal, Valais, Switzerland. Link to MinDat.org Location Data.

Name Origin:

Named for the elements in the composition, CAlcium, iron (Ferrum), and ARSenic.

Name Pronunciation:

Cafarsite + Pronunciation

Synonym:

ICSD 200144

PDF 19-197

Cafarsite Image

Images:

Cafarsite

Comments: Octahedron of cafarsite with a green coloration (?) on a gneiss matrix.
Location: Vasl D' Aosta, Italy. Scale: 4.6x4.5x3.2 cm.
© Isaias Casanova / IC Minerals

Images:

Cafarsite

Comments: Small, cubic crystal of cafarsite on matrix.
Location: Wannigletscher, Binntal, Switzerland. Scale: Crystal size 0.5 cm.
© Rob Lavinsky

Cafarsite Crystallography

Cell Dimensions:

a = 16.01, Z = 4; V = 4,103.69 Den(Calc)= 3.61

Crystal System:

Isometric - DiploidalH-M Symbol (2/m 3) Space Group: P n3

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

By Intensity(I/I_o): 2.83(1), 2.75(0.8), 3.15(0.7),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Edenharter A , Nowacki W , Weibel M , Schweizerische Mineralogische und Petrographische Mitteilungen , 57 (1977) p.1-16, Zur struktur und zusammensetzung von cafarsit, cafarsit ein As(III)-oxid,, kein arsenat, Locality: synthetic, Note: Water positions were not determined

Physical Properties of Cafarsite

Cleavage:

None

Color:

Brownish yellow, Brownish black, Dark brown, Dark red.

Density:

3.9

Diaphaneity:

Translucent to Opaque

Fracture:

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

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luster:

Sub Metallic

Streak:

yellowish brown

Optical Properties of Cafarsite

Optical Data:

NCalc= 1.92 - from Gladstone-Dale relationship (KC = 0.2541) where Ncalc=Dcalc*KC+1
NCalc= 1.99 - from Gladstone-Dale relationship (KC = 0.2541) where Ncalc=Dmeas*KC+1

Calculated Properties of Cafarsite

Electron Density:

Bulk Density (Electron Density)=3.40 gm/cc
note: Specific Gravity of Cafarsite =3.61 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Cafarsite= 33.41 barns/electron
U=PE_Cafarsite x rElectron Density= 113.73 barns/cc.

Radioactivity:

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

Cafarsite Classification

Dana Class:

45.01.04.01 (45)Acid and normal Antimonites, Arsenites and Phosphites

(45.01)with miscellaneous formulae

(45.01.04)Dana Group

45.01.04.01 Cafarsite Ca8(Ti,Fe,Fe,Mn)6-7(AsO3)12•4(H2O) P n3 2/m 3

Strunz Class:

04.JC.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.J - Arsenites, Antimonites, Bismuthites, Sulfites,

04.JC -Arsenites, antimonites, bismuthites; without additional anions, with H2O

04.JC.05 Cafarsite Ca8(Ti,Fe,Fe,Mn)6-7(AsO3)12•4(H2O) P n3 2/m 3

Other Cafarsite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

Search for Cafarsite using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Cafarsite :

AA Mineral Specimens

B & L Fine Minerals

Crystalarium.com

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Desert Winds Gems and Minerals

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

Wrights Rock Shop

Translate Cafarsite Mineral Data :

Ask about Cafarsite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Cafarsite

Ca8(Ti,Fe++,Fe+++,Mn)6-7(As+++O3)12•4(H2O)
Dana No: 45.01.04.01 Strunz No: 04.JC.05
Locality:

Notes: