Mineralogy Database

Atacamite Mineral Data

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General Atacamite Information

Help on Chemical  Formula: Chemical Formula: Cu2Cl(OH)3
Help on Composition: Composition: Molecular Weight = 213.57 gm
   Copper    59.51 %  Cu   74.49 % CuO
   Hydrogen   1.42 %  H    12.65 % H2O
   Chlorine  16.60 %  Cl   16.60 % Cl
               -   %   Cl   -3.75 % -O=Cl2   
   Oxygen    22.47 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Cu2Cl(OH)3
Help on Environment: Environment: Arid climates with oxidizable copper minerals.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1801
Help on Locality: Locality: Atacam desert province in northern Chile. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after its locality.
Help on Name Pronunciation: Name Pronunciation: Atacamite + Pronunciation Say ATACAMITE
Help on Synonym: Synonym: ICSD 61252
  PDF 25-269

Atacamite Image

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Comments: Atacamite in a well crystallized pocket.
Location: Mina Lily, Pisco Umay, Ica Dept. Peru. Scale: 5 x 4.5 cm.
© Fabre Minerals

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  Santarosaite   Atacamite

Comments: Encrustations of santarosaite (Cotype Specimen, MD212; blue) with atacamite (green) and anhydrite (white) on matrix. Discovered by Arturo Molina, Iquique, Chile in 2003. Holotype, sample MD 87, largely used up for the examinations.
Location: Santa Rosa Mine, Iquique, Chile. Scale: Sample Width 3 cm.
© K.C. Lyncker, Hamburg / German Type Specimen Catalogue

Atacamite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7491:1:0.6582
Help on Cell Dimensions: Cell Dimensions: a = 6.84, b = 9.13, c = 6.01, Z = 4; V = 375.32 Den(Calc)= 3.78
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pmcn
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.82(1), 5(1), 5.4(1),
Help on Forms: Forms:

Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize

S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu

Help on Above

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

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Physical Properties of Atacamite

Help on Cleavage: Cleavage: {010} Perfect
Help on Color: Color: Green, Yellow, Yellow green, Black green.
Help on Density: Density: 3.76 - 3.78, Average = 3.76
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Hardness: Hardness: 3-3.5 - Calcite-Copper Penny
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Adamantine
Help on Streak: Streak: apple green

Optical Properties of Atacamite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.024 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2268,KPDmeas= 0.2274,KC= 0.2221
Ncalc = 1.84
Help on Optical Data: Optical Data: Biaxial (-), a=1.831, b=1.861, g=1.88, bire=0.0490, 2V(Calc)=74, 2V(Meas)=75. Dispersion strong, r < v.

Calculated Properties of Atacamite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.61 gm/cc
note: Specific Gravity of Atacamite =3.78 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0001100017
Boson Index = 0.9998899983
Help on Photoelectric: Photoelectric: PEAtacamite = 27.37 barns/electron
U=PEAtacamite x rElectron Density= 98.83 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Atacamite is Not Radioactive

Atacamite Classification

Help on  Dana Class: Dana Class: (10)Oxyhalides and Hydroxyhalides
  (10.01)where (A)2 (O,OH)3 Xq
  (10.01.01)Atacamite group Atacamite Cu2Cl(OH)3 Pmcn 2/m 2/m 2/m Hibbingite (Fe,Mg)2(OH)3Cl Pnam 2/m 2/m 2/m Gillardite! Cu3NiCl2(OH)6 R 3m 3 Haydeeite! Cu3Mg(OH)6Cl2 R 3m 3
Help on  Strunz Class: Strunz Class: 03.DA.10a 03 - HALIDES
  03.D - Oxyhalides, Hydroxyhalides and Related Double Halides
  03.DA -With Cu, etc., without Pb
03.DA.10a Atacamite Cu2Cl(OH)3 Pmcn 2/m 2/m 2/m
03.DA.10a Hibbingite (Fe,Mg)2(OH)3Cl Pnam 2/m 2/m 2/m
03.DA.10a Kempite Mn2Cl(OH)3 Pnam 2/m 2/m 2/m

Other Atacamite Information

Help on References: References: NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Atacamite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - Franklin Minerals(Dunn)
7 - GeoScienceWorld
8 - Glendale Community College
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - Philatelic Mineralogy
17 - QUT Mineral Atlas
18 - Ruff.Info
20 - YupRocks
21 - theimage

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Dana No: Strunz No: 03.DA.10a





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