Picromerite Mineral Data
General Picromerite Information
Chemical Formula:
K2Mg(SO4)2•6(H2O)
Composition:
Molecular Weight = 402.72 gm
Potassium 19.42 % K 23.39 % K2 O
Magnesium 6.04 % Mg 10.01 % MgO
Hydrogen 3.00 % H 26.84 % H2 O
Sulfur 15.92 % S 39.76 % SO3
Oxygen 55.62 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
K2 Mg(SO4 )2 •6(H2 O)
Environment:
Volcanic fumaroles and marine evaporite deposits.
IMA Status:
Valid Species (Pre-IMA) 1855
Locality:
Vesuvius, Italy Link to MinDat.org Location Data.
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.
Name Pronunciation:
Picromerite + Pronunciation
Synonym:
ICSD 26772
PDF 21-1400
Schoenite
Picromerite Image
Images:
Picromerite
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
Axial Ratios:
a:b:c =0.7395:1:0.4987
Cell Dimensions:
a = 9.064, b = 12.256, c = 6.113, Z = 2; beta = 104.8° V = 656.55 Den(Calc)= 2.04
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /a
X Ray Diffraction:
By Intensity(I/Io ): 3.706(1), 4.064(0.95), 4.156(0.85),
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 1)
( 1 1 1)
( 0 1 0)
( 2 0 1)
( 1 1 0)
( 1 0 0)
( 0 0 1)
Warning: this java applet does not work in some browsers because of security restrictions.
Physical Properties of Picromerite
Cleavage:
{201} Perfect
Color:
Colorless, Gray, Yellow, White, Reddish.
Density:
2.028
Diaphaneity:
Transparent
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Hardness:
2.5 - Finger Nail
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Picromerite
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
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
Electron Density:
Bulk Density (Electron Density)=2.09 gm/cc note: Specific Gravity of Picromerite =2.04 gm/cc.
Fermion Index:
Fermion Index = 0.0075243351 Boson Index = 0.9924756649
Photoelectric:
PEPicromerite = 3.04 barns/electronU=PEPicromerite x r electron = 6.35 barns/cc.
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
Dana Class:
29.03.06.01 (29) Hydrated Acid and Sulfates
(29.03) where (A+)2 B (XO4)2 � x(H2O)
(29.03.06) Dana Group
29.03.06.01 Picromerite K2Mg(SO4)2•6(H2O) P 21 /a 2/m
29.03.06.02 Cyanochroite K2Cu(SO4)2•6(H2O) P 21 /a 2/m
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
References:
NAME( Dana7) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
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
Search for Picromerite using:
[AOL ]
[Bing ]
[Dog Pile ]
[GeoScienceWorld ]
[HotBot ]
[Ixquick ]
[Lycos ]
[MAMMA ]
[Scirus ]
[Teoma ]
[WebCrawler ]
[Wikipedia ]
[YAHOO ]
Visit our Advertisers for Picromerite :
Ask about Picromerite 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
Espa�ol
Print or Cut-and-Paste your Picromerite Specimen Label here :
Picromerite
K2Mg(SO4)2•6(H2O)
Dana No: 29.03.06.01 Strunz No: 07.CC.60
Locality:
Notes:
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.