Vanthoffite Mineral Data

General Vanthoffite Information

Chemical Formula:

Na6Mg(SO4)4

Composition:

Molecular Weight = 546.50 gm

Sodium 25.24 % Na 34.02 % Na₂O

Magnesium 4.45 % Mg 7.38 % MgO

Sulfur 23.47 % S 58.60 % SO₃

Oxygen 46.84 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₆Mg(SO₄)₄

Environment:

Marine evaporite mineral.

IMA Status:

Valid Species (Pre-IMA) 1902

Locality:

Wilhelmshall, Stassfurt region, Germany. Link to MinDat.org Location Data.

Name Origin:

Named for Jacobus Hendricus van't Hoff (1852-1911), Dutch physical chemist.

Name Pronunciation:

Vanthoffite + Pronunciation

Synonym:

ICSD 16607

PDF 29-1240

Vanthoffite Image

Images:

Vanthoffite

Comments: Colorless to white fragment of vanthoffite.
Location: Berlepsch Mine, Stassfurt, Stassfurt Deposit, Saxony-Anhalt, Germany. Scale: Picture size 7 mm.
© Thomas Witzke / Abraxas-Verlag

Vanthoffite Crystallography

Axial Ratios:

a:b:c =1.0629:1:0.8895

Cell Dimensions:

a = 9.797, b = 9.217, c = 8.199, Z = 2; beta = 113.3° V = 679.98 Den(Calc)= 2.67

Crystal System:

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

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

By Intensity(I/I_o): 2.91(1), 3.43(0.95), 3.44(0.95),

Physical Properties of Vanthoffite

Color:

Colorless.

Density:

2.694

Diaphaneity:

Transparent

Fracture:

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

Habit:

Friable - Loosley cohesive material that granulates with your fingers.

Habit:

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

Hardness:

3.5 - Copper Penny

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Vanthoffite

Gladstone-Dale:

CI meas= 0.009 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.001 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.183,KPDmeas= 0.1814,KC= 0.1831
Ncalc = 1.49

Optical Data:

Biaxial (-), a=1.488, b=1.489, g=1.489, bire=0.0010, 2V(Calc)=0, 2V(Meas)=84. Dispersion r < v weak.

Calculated Properties of Vanthoffite

Electron Density:

Bulk Density (Electron Density)=2.64 gm/cc
note: Specific Gravity of Vanthoffite =2.67 gm/cc.

Fermion Index:

Fermion Index = 0.0064325127
Boson Index = 0.9935674873

Photoelectric:

PE_Vanthoffite= 1.92 barns/electron
U=PE_Vanthoffite x rElectron Density= 5.07 barns/cc.

Radioactivity:

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

Vanthoffite Classification

Dana Class:

28.04.01.01 (28)Anhydrous Acid and Sulfates

(28.04)with miscellaneous formulae

(28.04.01)Dana Group

28.04.01.01 Vanthoffite Na6Mg(SO4)4 P 2₁/c 2/m

Strunz Class:

07.AC.05 07 - SULFATES (SELENATES, TELLURATES)

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

07.AC -With medium-sized and large cations

07.AC.05 Vanthoffite Na6Mg(SO4)4 P 2₁/c 2/m

Other Vanthoffite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Vanthoffite :
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 Vanthoffite Specimen Label here :

Vanthoffite

Na6Mg(SO4)4
Dana No: 28.04.01.01 Strunz No: 07.AC.05
Locality:

Notes:

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