Hexahydrite Mineral Data

[How the Club Works] [Memberships - Junior, Deluxe , and Platinum] [FAQ] [Past Minerals]
Join the Club - Junior, Deluxe and Platinum Memberships Available
High Quality Minerals Sent to Your Home or School Each Month
Mineral of the Month Club - An Inexpensive Way to Enjoy Minerals

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."

Name Pronunciation:

Hexahydrite + Pronunciation

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

Diaphaneity:

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:

Non-fluorescent.

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
Ncalc = 1.44 - 1.45

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:

Bulk Density (Electron Density)=1.81 gm/cc
note: Specific Gravity of Hexahydrite =1.72 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Hexahydrite= 1.21 barns/electron
U=PE_Hexahydrite x rElectron Density= 2.19 barns/cc.

Radioactivity:

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

Hexahydrite Classification

Dana Class:

29.06.08.01 (29)Hydrated Acid and Sulfates

(29.06)where A XO4 · x(H2O)

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

29.06.08.01 Hexahydrite MgSO4•6(H2O) A2/a 2/m

29.06.08.02 Bianchite (Zn,Fe)(SO4)•6(H2O) C 2/c 2/m

29.06.08.03 Ferrohexahydrite FeSO4•6(H2O) C 2/c 2/m

29.06.08.04 Nickelhexahydrite (Ni,Mg,Fe)(SO4)•6(H2O) C 2/c 2/m

29.06.08.05 Moorhouseite (Co,Ni,Mn)SO4•6(H2O) C 2/c 2/m

29.06.08.06 Chvaleticeite (Mn,Mg)SO4•6(H2O) C 2/c 2/m

Strunz Class:

07.CB.25 07 - SULFATES (SELENATES, TELLURATES)

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

07.CB -With only medium-sized cations

07.CB.25 Bianchite (Zn,Fe)(SO4)•6(H2O) C 2/c 2/m

07.CB.25 Ferrohexahydrite FeSO4•6(H2O) C 2/c 2/m

07.CB.25 Chvaleticeite (Mn,Mg)SO4•6(H2O) C 2/c 2/m

07.CB.25 Hexahydrite MgSO4•6(H2O) A2/a 2/m

07.CB.25 Moorhouseite (Co,Ni,Mn)SO4•6(H2O) C 2/c 2/m

07.CB.25 Nickelhexahydrite (Ni,Mg,Fe)(SO4)•6(H2O) C 2/c 2/m

Other Hexahydrite Information

References:

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

See Also:

Links to other databases for Hexahydrite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - MinMax(Deutsch)
12 - MinMax(English)
13 - Mineralienatlas (Deutsch)
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

Search for Hexahydrite using:

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

Visit our Advertisers for Hexahydrite :

AA Mineral Specimens

B & L Fine Minerals

Crystalarium.com

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Desert Winds Gems and Minerals

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

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: 29.06.08.01 Strunz No: 07.CB.25
Locality:

Notes: