Changoite Mineral Data

General Changoite Information

Chemical Formula:

Na2Zn(SO4)2•4(H2O)

Composition:

Molecular Weight = 375.56 gm

Sodium 12.24 % Na 16.50 % Na₂O

Zinc 17.41 % Zn 21.67 % ZnO

Hydrogen 2.15 % H 19.19 % H₂O

Sulfur 17.08 % S 42.64 % SO₃

Oxygen 51.12 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂Zn(SO₄)₂•4(H₂O)

Environment:

Found as a product of oxidation in an old mining area. The zinc-dominant analogue of blï¿½dite and nickelblï¿½dite.

IMA Status:

Approved IMA 1998 (Dana # Added)

Locality:

2 km west of Sierra Gorda, northeast of Antofagasta, northern Chile. Link to MinDat.org Location Data.

Name Origin:

Named after the changos, the early former inhabitants of northern Chile.

Synonym:

IMA1997-041

Changoite Crystallography

Axial Ratios:

a:b:c =1.3428:1:0.6706

Cell Dimensions:

a = 11.077, b = 8.249, c = 5.532, Z = 2; beta = 100.183° V = 497.52 Den(Calc)= 2.51

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/a

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

By Intensity(I/I_o): 3.289(1), 4.55(0.58), 3.262(0.35),

Physical Properties of Changoite

Color:

Colorless.

Density:

2.5

Diaphaneity:

Transparent

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

Water Soluble - Water soluble mineral.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Changoite

Gladstone-Dale:

CI meas= 0.007 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.011 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.204,KPDmeas= 0.2048,KC= 0.2063
Ncalc = 1.52

Optical Data:

Biaxial (-), a=1.507, b=1.512, g=1.517, bire=0.0100

Calculated Properties of Changoite

Electron Density:

Bulk Density (Electron Density)=2.50 gm/cc
note: Specific Gravity of Changoite =2.50 gm/cc.

Fermion Index:

Fermion Index = 0.0086680282
Boson Index = 0.9913319718

Photoelectric:

PE_Changoite= 9.60 barns/electron
U=PE_Changoite x rElectron Density= 24.03 barns/cc.

Radioactivity:

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

Changoite Classification

Dana Class:

29.03.03.05 (29)Hydrated Acid and Sulfates

(29.03)where (A+)2 B (XO4)2 ï¿½ x(H2O)

(29.03.03)Blodite Group

29.03.03.01 Blodite Na2Mg(SO4)2•4(H2O) P 2₁/a 2/m

29.03.03.02 Nickelblodite Na2(Ni,Mg)(SO4)2•4(H2O) P 2₁/a 2/m

29.03.03.03 Leonite K2Mg(SO4)2•4(H2O) C 2/m 2/m

29.03.03.04 Mereiterite! K2Fe(SO4)2•4(H2O) C 2/m 2/m

29.03.03.05 Changoite! Na2Zn(SO4)2•4(H2O) P 2₁/a 2/m

Strunz Class:

07.CC.50 07 - SULFATES (SELENATES, TELLURATES)

07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O

07.CC -With medium-sized and large cations

07.CC.50 Blodite Na2Mg(SO4)2•4(H2O) P 2₁/a 2/m

07.CC.50 Changoite! Na2Zn(SO4)2•4(H2O) P 2₁/a 2/m

07.CC.50 Nickelblodite Na2(Ni,Mg)(SO4)2•4(H2O) P 2₁/a 2/m

Other Changoite Information

References:

NAME( CanMin 8/1999) PHYS. PROP.(AmMin, V84, p. 1685) OPTIC PROP.(MinRec)

See Also:

Links to other databases for Changoite :
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

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

Changoite

Na2Zn(SO4)2•4(H2O)
Dana No: 29.03.03.05 Strunz No: 07.CC.50
Locality:

Notes:

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