Mineralogy Database

Epsomite Mineral Data

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General Epsomite Information

Help on Chemical  Formula: Chemical Formula: MgSO4•7(H2O)
Help on Composition: Composition: Molecular Weight = 246.48 gm
   Magnesium   9.86 %  Mg   16.35 % MgO
   Hydrogen    5.73 %  H    51.16 % H2O
   Sulfur     13.01 %  S    32.48 % SO3
   Oxygen     71.40 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg(SO4)•7(H2O)
Help on Environment: Environment: White efflorescence on cave walls, volcanic exhalations, or deposited by Mg sulfate spring waters.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1824
Help on Locality: Locality: Lake-bed deposits on Kruger Mountain, Oregon. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: The mineral has long been known from the deposits associated with the mineral waters at Epsom, Surrey, England.
Help on Name Pronunciation: Name Pronunciation: Epsomite Say EPSOMITE
Help on Synonym: Synonym: Bitter Salt
  Epsom Salts
  ICSD 29384
  PDF 36-419
  Reichardite - massive

Epsomite Image

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Comments: Pure white compact fibrous mass of epsomite.
Location: Calatayud, Zaragoza, Aragon, Spain. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Epsomite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9891:1:0.5719
Help on Cell Dimensions: Cell Dimensions: a = 11.86, b = 11.99, c = 6.858, Z = 4; V = 975.22 Den(Calc)= 1.68
Help on Crystal System: Crystal System: Orthorhombic - Disphenoidal H-M Symbol (2 2 2) Space Group: P 212121
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.21(1), 2.677(0.25), 5.35(0.25),
Help on Forms: Forms:

Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize

S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu

Help on Above

Forms: ( 0 1 0) ( 1 0 1) ( 1 0 0)

Warning: this java applet does not work in some browsers because of security restrictions.


Physical Properties of Epsomite

Help on Cleavage: Cleavage: {010} Perfect, {101} Distinct
Help on Color: Color: Colorless, White, Yellowish white, Greenish white, Pinkish white.
Help on Density: Density: 1.67 - 1.68, Average = 1.67
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Habit: Habit: Encrustations - Forms crust-like aggregates on matrix.
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Hardness: Hardness: 2-2.5 - Gypsum-Finger Nail
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: white

Optical Properties of Epsomite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.016 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.013 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2677,KPDmeas= 0.2685,KC= 0.2642
Ncalc = 1.44
Help on Optical Data: Optical Data: Biaxial (-), a=1.433, b=1.455, g=1.461, bire=0.0280, 2V(Calc)=54, 2V(Meas)=52. Dispersion none.
Help on Pleochroism (x): Pleochroism (x): none.
Help on Pleochroism (y): Pleochroism (y): none.

Calculated Properties of Epsomite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=1.77 gm/cc
note: Specific Gravity of Epsomite =1.68 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEEpsomite = 1.14 barns/electron
U=PEEpsomite x rElectron Density= 2.03 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Epsomite is Not Radioactive

Epsomite Classification

Help on  Dana Class: Dana Class: (29)Hydrated Acid and Sulfates
  (29.06)where A XO4 � x(H2O)
  (29.06.11)Epsomite Group Epsomite MgSO4•7(H2O) P 212121 2 2 2 Goslarite ZnSO4•7(H2O) P 212121 2 2 2 Morenosite NiSO4•7(H2O) P 212121 2 2 2
Help on  Strunz Class: Strunz Class: 07.CB.40 07 - SULFATES (SELENATES, TELLURATES)
  07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O
  07.CB -With only medium-sized cations
07.CB.40 Epsomite MgSO4•7(H2O) P 212121 2 2 2
07.CB.40 Goslarite ZnSO4•7(H2O) P 212121 2 2 2
07.CB.40 Morenosite NiSO4•7(H2O) P 212121 2 2 2

Other Epsomite Information

Help on See Also: See Also: Links to other databases for Epsomite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - Franklin Minerals(Dunn)
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineral and Gemstone Kingdom
14 - Mineralienatlas (Deutsch)
15 - NSDL Reciprocal Net (JAVA)
16 - Online Mineral Museum
17 - QUT Mineral Atlas
18 - Ruff.Info

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Dana No: Strunz No: 07.CB.40





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