Hexahydrite Mineral Data

Hexahydrite Mineral Data +

[Newest Minerals] [Equipment] [Analytical Services] [About Us] [Mineral Gallery] [eBay Store]
See Also: [Diamond Crystals] [Mineral News] [Hudson Institute] [Minerals on CDROM]
Rare Minerals, Meteorites, Equipment and Analytical Services
Excalibur Mineral Company, World leaders in the supply of rare species
Serving the scientific and collector communities since 1974

General Hexahydrite Information

Chemical Formula:

MgSO4·6(H2O)

Composition:

Molecular Weight = 228.46 gm

Magnesium 10.64 % Mg 17.64 % MgO

Hydrogen 5.29 % H 47.31 % H₂O

Sulfur 14.04 % S 35.05 % SO₃

Oxygen 70.03 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg(SO₄)·6(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1911

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named after the number of water molecules hexa, "six" and hydor, "water."

Synonym:

Bitter Salt

ICSD 16546

Magnesium Sulphate

PDF 24-719

Hexahydrite Image

Images:

Hexahydrite

Comments: White fibrous mats and powdery encrustation of hexahydrite on matrix.
Location: near Basque, Bonaparte River, British Columbia, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Hexahydrite Crystallography

Axial Ratios:

a:b:c =3.3871:1:1.4023

Cell Dimensions:

a = 24.442, b = 7.216, c = 10.119, Z = 8; beta = 98.28° V = 1,766.12 Den(Calc)= 1.72

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: A2/a

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

By Intensity(I/I_o): 4.39(1), 5.45(0.5), 5.1(0.45),

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

Zalkin A , Ruben H , Templeton D H , Acta Crystallographica , 17 (1964) p.235-240, The crystal structure and hydrogen bonding of magnesium sulfate hexahydrate, Locality: synthetic

Physical Properties of Hexahydrite

Cleavage:

[010] Perfect, [101] Distinct

Color:

Colorless, White, Greenish white.

Density:

1.76

Diaphaniety:

Opaque

Fracture:

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

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Fibrous - Crystals made up of fibers.

Hardness:

2-2.5 - Gypsum-Finger Nail

Luminescence:

None.

Luster:

Vitreous (Glassy)

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Hexahydrite

Gladstone-Dale:

CI meas= 0.021 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.002 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2587,KPDmeas= 0.2528,KC= 0.2582

Optical Data:

Biaxial (-), a=1.426, b=1.453, g=1.456, bire=0.0300, 2V(Calc)=36, 2V(Meas)=38. Dispersion none.

Pleochroism (x):

none.

Calculated Properties of Hexahydrite

Electron Density:

r_electron=1.81 gm/cc
note: r_Hexahydrite=1.72 gm/cc.

Fermion Index

Fermion Index = 0.01203
Boson Index = 0.98797

Photoelectric:

PE_Hexahydrite= 1.21 barns/electron
U=PE_Hexahydrite x r_electron= 2.19 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Hexahydrite is Not Radioactive

Hexahydrite Classification

Dana Class:

29.6.8.1 (29)Hydrated Acid and Sulfates

(29.6)where A XO4 · x(H2O)

(29.6.8)Hexahydrite Group (Space Group: C2/c)

29.6.8.1 Hexahydrite MgSO4·6(H2O) A2/a 2/m

29.6.8.2 Bianchite (Zn,Fe)(SO4)·6(H2O) C 2/c 2/m

29.6.8.3 Ferrohexahydrite FeSO4·6(H2O) C 2/c 2/m

29.6.8.4 Nickelhexahydrite (Ni,Mg,Fe)(SO4)·6(H2O) C 2/c 2/m

29.6.8.5 Moorhouseite (Co,Ni,Mn)SO4·6(H2O) C 2/c 2/m

29.6.8.6 Chvaleticeite (Mn,Mg)SO4·6(H2O) C 2/c 2/m

Strunz Class:

VI/C.05-10 VI - Sulfates,Chromates,Molybdates and Tungstates

VI/C - Water-bearing sulfates without unfamiliar anions. cations of medium size

VI/C.05 - Hexahydrite group

VI/C.05-10 Hexahydrite MgSO4·6(H2O) A2/a 2/m

VI/C.05-20 Ferrohexahydrite FeSO4·6(H2O) C 2/c 2/m

VI/C.05-30 Chvaleticeite (Mn,Mg)SO4·6(H2O) C 2/c 2/m

VI/C.05-40 Moorhouseite (Co,Ni,Mn)SO4·6(H2O) C 2/c 2/m

VI/C.05-50 Nickelhexahydrite (Ni,Mg,Fe)(SO4)·6(H2O) C 2/c 2/m

VI/C.05-60 Bianchite (Zn,Fe)(SO4)·6(H2O) C 2/c 2/m

VI/C.05-70 Retgersite NiSO4·6(H2O) P 4₁2₁2,P 4₃2₁2 4 2 2

Other Hexahydrite Information

References:

NAME( Mason68) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

Search for Hexahydrite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Hexahydrite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Hexahydrite Mineral Data :

Ask about Hexahydrite 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 Hexahydrite Specimen Label here :

Hexahydrite

MgSO4·6(H2O)
Dana No: 29.6.8.1 Strunz No: VI/C.05-10
Locality:

Notes: