Mineralogy Database

Picromerite Mineral Data

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General Picromerite Information

Help on Chemical  Formula: Chemical Formula: K2Mg(SO4)2•6(H2O)
Help on Composition: Composition: Molecular Weight = 402.72 gm
   Potassium  19.42 %  K    23.39 % K2O
   Magnesium   6.04 %  Mg   10.01 % MgO
   Hydrogen    3.00 %  H    26.84 % H2O
   Sulfur     15.92 %  S    39.76 % SO3
   Oxygen     55.62 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K2Mg(SO4)2•6(H2O)
Help on Environment: Environment: Volcanic fumaroles and marine evaporite deposits.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1855
Help on Locality: Locality: Vesuvius, Italy Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek for "bitter" and "part" in allusion to the magnesium content which makes this water-soluble salt bitter to the taste.
Help on Name Pronunciation: Name Pronunciation: Picromerite + Pronunciation Say PICROMERITE
Help on Synonym: Synonym: ICSD 26772
  PDF 21-1400

Picromerite Image

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Comments: Blocky white picromerite crystals on reddish halite.
Location: Heringen, Werra Valley, North Hesse, Hesse, Germany. Scale: Specimen Size 5.5 x 4.7 x 3.4 cm.
© Rob Lavinsky

Picromerite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7395:1:0.4987
Help on Cell Dimensions: Cell Dimensions: a = 9.064, b = 12.256, c = 6.113, Z = 2; beta = 104.8° V = 656.55 Den(Calc)= 2.04
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/a
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.706(1), 4.064(0.95), 4.156(0.85),
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 1) ( 1 1 1) ( 0 1 0) ( 2 0 1) ( 1 1 0) ( 1 0 0) ( 0 0 1)

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Physical Properties of Picromerite

Help on Cleavage: Cleavage: {201} Perfect
Help on Color: Color: Colorless, Gray, Yellow, White, Reddish.
Help on Density: Density: 2.028
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Hardness: Hardness: 2.5 - Finger Nail
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Picromerite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.005 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2286,KPDmeas= 0.23,KC= 0.2275
Ncalc = 1.46
Help on Optical Data: Optical Data: Biaxial (+), a=1.4607, b=1.4629, g=1.4755, bire=0.0148, 2V(Calc)=46, 2V(Meas)=47.9.

Calculated Properties of Picromerite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.09 gm/cc
note: Specific Gravity of Picromerite =2.04 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0075243351
Boson Index = 0.9924756649
Help on Photoelectric: Photoelectric: PEPicromerite = 3.04 barns/electron
U=PEPicromerite x relectron= 6.35 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 286.60 (Gamma Ray American Petroleum Institute Units)
Concentration of Picromerite per GRapi unit = 0.35 (%)

Estimated Radioactivity from Picromerite - barely detectable


Picromerite Classification

Help on  Dana Class: Dana Class: (29)Hydrated Acid and Sulfates
  (29.03)where (A+)2 B (XO4)2 � x(H2O)
  (29.03.06)Dana Group Picromerite K2Mg(SO4)2•6(H2O) P 21/a 2/m Cyanochroite K2Cu(SO4)2•6(H2O) P 21/a 2/m
Help on  Strunz Class: Strunz Class: 07.CC.60 07 - SULFATES (SELENATES, TELLURATES)
  07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O
  07.CC -With medium-sized and large cations
07.CC.60 Boussingaultite (NH4)2Mg(SO4)2•6(H2O) P 21/a 2/m
07.CC.60 Cyanochroite K2Cu(SO4)2•6(H2O) P 21/a 2/m
07.CC.60 Mohrite (NH4)2Fe(SO4)2•6(H2O) P 21/c 2/m
07.CC.60 Picromerite K2Mg(SO4)2•6(H2O) P 21/a 2/m
07.CC.60 Nickelboussingaultite (NH4)2(Ni,Mg)(SO4)2•6(H2O) P 21/a 2/m

Other Picromerite Information

Help on References: References: NAME( Dana7) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Picromerite :
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

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Dana No: Strunz No: 07.CC.60





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