Polyhalite  Mineral Data

Polyhalite Mineral Data

Search Webmineral :
   
Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images Share
      News Help About

Advertisment
Weinrich Minerals, A Dealer in Fine Mineral Specimens - Since 1989. We buy collections and single high quality specimens.
Dakota Matrix was founded in 1996 and has offered systematic and rare mineral specimens online since 1998.
Exceptional Minerals features excellent, high quality mineral specimens for sale. We also have a weekly Best Offer Mineral Auction.
McDougall Minerals sells high-quality mineral specimens from all over the world to collectors of all levels, from beginners to connoisseurs

General Polyhalite Information

Help on Chemical  Formula: Chemical Formula: K2Ca2Mg(SO4)4•2(H2O)
Help on Composition: Composition: Molecular Weight = 602.94 gm
   Potassium  12.97 %  K    15.62 % K2O
   Calcium    13.29 %  Ca   18.60 % CaO
   Magnesium   4.03 %  Mg    6.68 % MgO
   Hydrogen    0.67 %  H     5.98 % H2O
   Sulfur     21.27 %  S    53.12 % SO3
   Oxygen     47.76 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K2Ca2Mg(SO4)4•2(H2O)
Help on Environment: Environment: Sedimentary marine evaporite deposits.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1818
Help on Locality: Locality: Potash beds near Carlsbad, New Mexico. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek, polys, meaning "much" and hals, meaning "salt." in allusion to the many salt components in the formulae..
Help on Name Pronunciation: Name Pronunciation: Polyhalite + Pronunciation Say POLYHALITE
Help on Synonym: Synonym: ICSD 6303
  PDF 21-982
 

Polyhalite Image

Click Here for Larger Polyhalite Image in a New Browser Window Images:
Click Here for Larger Polyhalite Image

Polyhalite

Comments: White crystals of polyhalite in matrix.
Location: Ronneburg U deposit, Gera district, Thuringia, Germany. Scale: Picture size 1.5 mm.
© Thomas Witzke / Abraxas-Verlag

Polyhalite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7158:1:0.4654
Help on Cell Dimensions: Cell Dimensions: a = 11.69, b = 16.33, c = 7.6, Z = 4; alpha = 91.6°, beta = 90°, gamma = 91.9° V = 1,449.46 Den(Calc)= 2.76
Help on Crystal System: Crystal System: TriclinicSpace Group: P 1,P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.9(1), 3.18(0.7), 2.85(0.16),
Help on Forms: Forms:

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

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

Help on Above

Forms: ( 0 1 0) ( 1 3 1) ( 1 1 0) ( 1 0 0) ( 0 0 1)

Warning: this large pop-up is very compute intensive and may not work well with some computers.

Click Here for Large Polyhalite Structure Window 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


Bindi L , Acta Crystallographica, Section E , 61 (2005) p.i135-i136, Reinvestigation of the crystal structure of polyhalite, K2Ca2Mg(SO4)4*2H2O

View Additional jPOWD Structure files for Polyhalite
[1]
 

Physical Properties of Polyhalite

Help on Cleavage: Cleavage: {101} Perfect
Help on Color: Color: Colorless, Gray, Gray white, White, Pink.
Help on Density: Density: 2.77 - 2.78, Average = 2.77
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Massive - Fibrous - Distinctly fibrous fine-grained forms.
Help on Habit: Habit: Massive - Lamellar - Distinctly foliated fine-grained forms.
Help on Hardness: Hardness: 2.5-3.5 - Finger Nail-Copper Penny
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white
 

Optical Properties of Polyhalite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.019 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2022,KPDmeas= 0.2011,KC= 0.1974
Ncalc = 1.54 - 1.55
Help on Optical Data: Optical Data: Biaxial (-), a=1.546-1.548, b=1.558-1.562, g=1.567, bire=0.0190-0.0210, 2V(Calc)=60-80, 2V(Meas)=60-62.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
Help on Pleochroism (z): Pleochroism (z): colorless.
 

Calculated Properties of Polyhalite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.78 gm/cc
note: Specific Gravity of Polyhalite =2.78 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0060518431
Boson Index = 0.9939481569
Help on Photoelectric: Photoelectric: PEPolyhalite = 4.30 barns/electron
U=PEPolyhalite x relectron= 11.94 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 187.47 (Gamma Ray American Petroleum Institute Units)
Concentration of Polyhalite per GRapi unit = 0.53 (%)

Estimated Radioactivity from Polyhalite - barely detectable

 

Polyhalite Classification

Help on  Dana Class: Dana Class: 29.04.05.01 (29)Hydrated Acid and Sulfates
  (29.04)where (A+)2 Bn (XO4)p · x(H2O)
  (29.04.05)Dana Group
 
29.04.05.01 Polyhalite K2Ca2Mg(SO4)4•2(H2O) P 1,P1 Tri
 
29.04.05.02 Leightonite K2Ca2Cu(SO4)4•2(H2O) C 2/c 2/m
Help on  Strunz Class: Strunz Class: 07.CC.65 07 - SULFATES (SELENATES, TELLURATES)
  07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O
  07.CC -With medium-sized and large cations
 
07.CC.65 Polyhalite K2Ca2Mg(SO4)4•2(H2O) P 1,P1 Tri
 

Other Polyhalite Information

Help on References: References: NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Polyhalite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info

Search for Polyhalite using:

Google
 
Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Polyhalite :

A Bijoux Google Search for Polyhalite
Adam's Minerals Google Search for Polyhalite
Cape Minerals Google Search for Polyhalite
Dakota Matrix Minerals Google Search for Polyhalite
Excalibur Mineral Corp. Google Search for Polyhalite
Exceptional Minerals Google Search for Polyhalite
John Betts Fine Minerals Search for Polyhalite
McDougall Minerals Google Search for Polyhalite
Mineral News Website Link
Rock and Mineral Shows Google Search for Polyhalite
Weinrich Minerals, Inc. Google Search for Polyhalite

Ask about Polyhalite 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 Espaņol

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

Polyhalite

K2Ca2Mg(SO4)4•2(H2O)
Dana No: 29.04.05.01 Strunz No: 07.CC.65
Locality:

 

Notes: