Paratacamite Mineral Data

General Paratacamite Information

Chemical Formula:

(Cu,Zn)2(OH)3Cl

Composition:

Molecular Weight = 214.49 gm

Zinc 15.24 % Zn 18.97 % ZnO

Copper 44.44 % Cu 55.63 % CuO

Hydrogen 1.41 % H 12.60 % H₂O

Chlorine 16.53 % Cl 16.53 % Cl

- % Cl -3.73 % -O=Cl₂

Oxygen 22.38 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Cu_1.5Zn_0.5(OH)₃Cl

Environment:

Alteration of copper minerals by chloride waters under cold conditions.

IMA Status:

Valid Species (Pre-IMA) 1873

Locality:

Generosa and Herminia mines, Sierra Gorda, Chile. Link to MinDat.org Location Data.

Name Origin:

Named for the dimorphous relationship with atacamite.

Name Pronunciation:

Paratacamite + Pronunciation

Synonym:

ICSD 64956

PDF 25-325

Paratacamite Image

Images:

Christelite Paratacamite

Comments: Robins-egg blue christelite with dark green paratacamite on matrix.
Location: San Francisco mine, Sierra Gorda, Chile. Scale: 3 cm.
© John Veevaert

Images:

Paratacamite

Comments: Deep green crystal paratacamite rosettes on rusty quartz.
Location: Churchill Butte, Lyon County, Nevada, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Paratacamite Crystallography

Axial Ratios:

a:c = 1:1.02834

Cell Dimensions:

a = 13.654, c = 14.041, Z = 24; V = 2,266.98 Den(Calc)= 3.77

Crystal System:

Trigonal - Rhombohedral H-M Symbol ( 3) Space Group: R 3

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

By Intensity(I/I_o): 5.44(1), 2.27(0.8), 2.74(0.6),2.76(0.6), 2.78(0.5), 1.71(0.5), 2.9(0.3),

Physical Properties of Paratacamite

Cleavage:

{1011} Good

Color:

Greenish black, Dark green.

Density:

3.74

Diaphaneity:

Translucent to Subopaque

Fracture:

Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Habit:

Rhombohedral Crystals - Occurs as well-formed crystals showing rhobohedral crystals.

Hardness:

3 - Calcite

Luster:

Vitreous - Dull

Streak:

light green

Optical Properties of Paratacamite

Dichroism (e):

none.

Dichroism (w):

none.

Gladstone-Dale:

CI meas= -0.029 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2243,KPDmeas= 0.2261,KC= 0.2196
Ncalc = 1.82 - 1.83

Optical Data:

Uniaxial (+), w=1.843, e=1.848, bire=0.0050.

Calculated Properties of Paratacamite

Electron Density:

Bulk Density (Electron Density)=3.60 gm/cc
note: Specific Gravity of Paratacamite =3.77 gm/cc.

Fermion Index:

Fermion Index = 0.0063592515
Boson Index = 0.9936407485

Photoelectric:

PE_Paratacamite= 28.34 barns/electron
U=PE_Paratacamite x rElectron Density= 102.10 barns/cc.

Radioactivity:

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

Paratacamite Classification

Dana Class:

10.01.02.01 (10)Oxyhalides and Hydroxyhalides

(10.01)where (A)2 (O,OH)3 Xq

(10.01.02)Paratacamite Group

10.01.02.01 Paratacamite (Cu,Zn)2(OH)3Cl R 3 3

10.01.02.02 Clinoatacamite! Cu2(OH)3Cl P 2₁/n 2/m

10.01.02.03 Herbertsmithite! Cu3Zn(OH)6Cl2 R 3m 3 2/m

10.01.02.04 Kapellasite! Cu3Zn(OH)6Cl2 P 3m1 3 2/m

Strunz Class:

03.DA.10c 03 - HALIDES

03.D - Oxyhalides, Hydroxyhalides and Related Double Halides

03.DA -With Cu, etc., without Pb

03.DA.10c Paratacamite (Cu,Zn)2(OH)3Cl R 3 3

03.DA.10c Gillardite! Cu3NiCl2(OH)6 R 3m 3

03.DA.10c Herbertsmithite! Cu3Zn(OH)6Cl2 R 3m 3 2/m

03.DA.10c Kapellasite! Cu3Zn(OH)6Cl2 P 3m1 3 2/m

03.DA.10c Haydeeite! Cu3Mg(OH)6Cl2 R 3m 3

Other Paratacamite Information

References:

NAME( Dana8) PHYS. PROP.(AntBidBlaNic3) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Paratacamite :
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
15 - WWW-MINCRYST

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

Paratacamite

(Cu,Zn)2(OH)3Cl
Dana No: 10.01.02.01 Strunz No: 03.DA.10c
Locality:

Notes:

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