Gypsum Mineral Data + Say GYPSUM

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General Gypsum Information

Help on Chemical  Formula: Chemical Formula: CaSO42(H2O)
Help on Composition: Composition: Molecular Weight = 172.17 gm
   Calcium   23.28 %  Ca   32.57 % CaO
   Hydrogen   2.34 %  H    20.93 % H2O
   Sulfur    18.62 %  S    46.50 % SO3
   Oxygen    55.76 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca(SO4)2(H2O)
Help on Environment: Environment: Sedimentary evaporite deposits.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) Prehistoric
Help on Locality: Locality: Numerous localities worldwide. Naica, Chihuahua, Mexico. Link to Location Data.
Help on Name Origin: Name Origin: From the Greek, gyps meaning "burned" mineral. Selenite from the Greek in allusion to its pearly luster (moon light) on cleavage fragments.
Help on Synonym: Synonym: Alabaster
  ICSD 2057
  PDF 33-311
  Satin Spar

Gypsum Image

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Comments: Bladed rosettes of gypsum.
Location: unknown. Scale: Specimen size 6 cm.
Dave Barthelmy

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Comments: Pencil-sized acicular crystals of gypsum.
Location: Naica, Chihuahua, S.A., Mexico. Scale: Specimen size 5 cm.
Dave Barthelmy

Gypsum Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.3741:1:0.4143
Help on Cell Dimensions: Cell Dimensions: a = 5.68, b = 15.18, c = 6.29, Z = 4; beta = 113.833 V = 496.09 Den(Calc)= 2.31
Help on Crystal System: Crystal System: Monoclinic - PrismaticH-M Symbol (2/m) Space Group: A2/a
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 7.63(1), 4.28(1), 3.07(0.8),2.87(0.5), 2.69(0.4), 2.09(0.3), 2.22(0.2), 3.8(0.2),
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 1 1] [ 1 2 0]

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


Physical Properties of Gypsum

Help on Cleavage: Cleavage: [010] Perfect, [100] Distinct, [011] Distinct
Help on Color: Color: White, Colorless, Yellowish white, Greenish white, Brown.
Help on Density: Density: 2.3
Help on Diaphaniety: Diaphaniety: Transparent to translucent
Help on Fracture: Fracture: Fibrous - Thin, elongated fractures produced by crystal forms or intersecting cleavages (e.g. asbestos).
Help on Habit: Habit: Crystalline - Coarse - Occurs as well-formed coarse sized crystals.
Help on Habit: Habit: Massive - Fibrous - Distinctly fibrous fine-grained forms.
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 2 - Gypsum
Help on Luminescence: Luminescence: None.
Help on Luster: Luster: Pearly
Help on Streak: Streak: white

Optical Properties of Gypsum

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.027 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.022 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2268,KPDmeas= 0.2278,KC= 0.2219
Help on Optical Data: Optical Data: Biaxial (+), a=1.519-1.521, b=1.522-1.523, g=1.529-1.53, bire=0.0090-0.0100, 2V(Calc)=58-68, 2V(Meas)=58. Dispersion strong, r > v.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
Help on Pleochroism (z): Pleochroism (z): colorless.

Calculated Properties of Gypsum

Help on Electron Density: Electron Density:

relectron=2.36 gm/cc
note: rGypsum =2.31 gm/cc.

Help on Fermion Index Fermion Index Fermion Index = 0.00198
Boson Index = 0.99802
Help on Photoelectric: Photoelectric:

PEGypsum = 3.97 barns/electron
U=PEGypsum x relectron= 9.37 barns/cc.

Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Gypsum is Not Radioactive


Gypsum Classification

Help on  Dana Class: Dana Class: (29)Hydrated Acid and Sulfates
  (29.6)where A XO4 x(H2O)
  (29.6.3)Dana Group Gypsum CaSO42(H2O) A2/a 2/m
Help on  Strunz Class: Strunz Class: VI/C.22-20 VI - Sulfates,Chromates,Molybdates and Tungstates
  VI/C - Water-bearing sulfates without unfamiliar anions. Cations of very big size
  VI/C.22 - Bassanite - Ardealite series
VI/C.22-10 Bassanite 2CaSO4(H2O) Unk Ortho
VI/C.22-20 Gypsum CaSO42(H2O) A2/a 2/m
VI/C.22-25 Rapidcreekite Ca2(SO4)(CO3)4(H2O) Pcnb 2/m 2/m 2/m
VI/C.22-30 Ardealite Ca2(SO4)(HPO4)4(H2O) Cc m

Other Gypsum Information

Help on References: References: NAME( ODonoghue90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)
Help on See Also: See Also: Links to other databases for Gypsum :
1 - Alkali-Nuts(English) 2 -Am. Min. Crystal Structure Database 3 - Amethyst Galleries' Mineral Gallery 4 - Applied Mineralogy 5 -Athena 6 - Mineral Locations 7 - Franklin Minerals(Dunn) 8 - Franklin Minerals(Palache) 9 - Glendale Community College 10 -Google Images 11 -Google Scholar 12 -Handbook of Mineralogy (UofA) 13 - HyperPhysics 14 -MinDAT 15 -MinMax(Deutsch) 16 -MinMax(English) 17 -Mineral of the Month 18 -Mineralienatlas (Deutsch) 19 - Minerals of Wisconsin 20 -NSDL Reciprocal Net (JAVA) 21 - Philatelic Mineralogy 22 - Scandinavian mineral gallery 23 -U.S. Fish & Wildlife Service 24 -University of Colorado - Mineral Structure Data 25 - University of Manchester - Mineral Structure 26 -University of Minnesota 27 - WWW-MINCRYST 28 - YupRocks

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Babel Fish Translation

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Dana No: Strunz No: VI/C.22-20




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