Rollandite Mineral Data

General Rollandite Information

Chemical Formula:

Cu3(AsO4)2•4(H2O)

Composition:

Molecular Weight = 543.29 gm

Copper 36.26 % Cu 45.39 % CuO

Arsenic 27.58 % As 42.31 % As₂O₅

Hydrogen 1.41 % H 12.60 % H₂O

Oxygen 34.75 % O

______ ______

100.00 % 100.29 % = TOTAL OXIDE

Empirical Formula:

Cu_3.1(AsO₄)₂•3.8(H₂O)

Environment:

Secondary mineral in old Cu mines. New structure-type.

IMA Status:

Approved IMA 1998 (Dana # Added)

Locality:

Cu mines of Roua at the western margin of the Barrot Dome, Alpes-Maritimes, France. Link to MinDat.org Location Data.

Name Origin:

Named for Pierre Rolland (1940-), an eminent mineral collector of the Roua mines.

Synonym:

ICSD 90026

IMA1998-001

Search for Rollandite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Rollandite Crystallography

Axial Ratios:

a:b:c =0.3335:1:0.5704

Cell Dimensions:

a = 5.6906, b = 17.061, c = 9.732, Z = 4; V = 944.85 Den(Calc)= 3.82

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: P nma

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

By Intensity(I/I_o): 8.52(1)(020), 3.221(0.9)(141,051), 3.721(0.6)(131),3.102(0.4)(132), 2.795(0.35)(142), 2.817(0.35)(103,033), 2.133(0.25)(080,251), 2.35(0.25)(143,053), 2.366(0.2)(240,071),

Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: ( 0 1 0) ( 1 0 1) ( 1 0 0) ( 0 1 1) ( 0 0 1)

Warning: this large pop-up is very compute intensive and may not work well with some computers.

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

Sarp H , Cerny R , European Journal of Mineralogy , 12 (2000) p.1045-1050, Rollandite, Cu3(AsO4)2.4H2O, a new mineral: its description and crystal structure

Physical Properties of Rollandite

Cleavage:

{001} Good

Color:

Bottle green.

Density:

3.9

Diaphaneity:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Hardness:

4-4.5 - Between Fluorite and Apatite

Luster:

Vitreous (Glassy)

Streak:

light green

Optical Properties of Rollandite

Gladstone-Dale:

CI meas= -0.025 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.046 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1972,KPDmeas= 0.1932,KC= 0.1885
Ncalc = 1.72 - 1.74

Optical Data:

Biaxial (-), a=1.745, b=1.755, g=1.76, bire=0.0150, 2V(Calc)=70, 2V(Meas)=71. Dispersion strong, r < v.

Calculated Properties of Rollandite

Electron Density:

Bulk Density (Electron Density)=3.70 gm/cc
note: Specific Gravity of Rollandite =3.90 gm/cc.

Fermion Index:

Fermion Index = 0.000168915
Boson Index = 0.999831085

Photoelectric:

PE_Rollandite= 34.93 barns/electron
U=PE_Rollandite x rElectron Density= 129.32 barns/cc.

Radioactivity:

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

Rollandite Classification

Dana Class:

40.03.04.02 (40)Hydrated Phosphates, etc

(40.03)where (A++)3 (XO4)2 · x(H2O)

(40.03.04)Hopeite Group

40.03.04.01 Hopeite Zn3(PO4)2•4(H2O) P nma 2/m 2/m 2/m

40.03.04.02 Rollandite! Cu3(AsO4)2•4(H2O) P nma 2/m 2/m 2/m

Strunz Class:

08.CD.30 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CD -With only medium-sized cations, RO4:H2O = 1:2

08.CD.30 Rollandite! Cu3(AsO4)2•4(H2O) P nma 2/m 2/m 2/m

Other Rollandite Information

References:

NAME( AmMin, vol 86, p 768) PHYS. PROP.(AmMin, vol 86, p 768) OPTIC PROP.(AmMin, vol 86, p 768)

See Also:

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

Search for Rollandite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Rollandite :

A Bijoux Google Search for Rollandite
Adam's Minerals Google Search for Rollandite
Cape Minerals Google Search for Rollandite
Dakota Matrix Minerals Google Search for Rollandite
Excalibur Mineral Corp. Google Search for Rollandite
Exceptional Minerals Google Search for Rollandite
John Betts Fine Minerals Search for Rollandite
McDougall Minerals Google Search for Rollandite
Mineral News Website Link
Rock and Mineral Shows Google Search for Rollandite
Weinrich Minerals, Inc. Google Search for Rollandite

Ask about Rollandite 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 Rollandite Specimen Label here :

Rollandite

Cu3(AsO4)2•4(H2O)
Dana No: 40.03.04.02 Strunz No: 08.CD.30
Locality:

Notes: