Mineralogy Database

Anhydrite Mineral Data

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General Anhydrite Information

Help on Chemical  Formula: Chemical Formula: CaSO4
Help on Composition: Composition: Molecular Weight = 136.14 gm
   Calcium  29.44 %  Ca   41.19 % CaO
   Sulfur   23.55 %  S    58.81 % SO3
   Oxygen   47.01 %  O
           ______        ______ 
           100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca(SO4)
Help on Environment: Environment: Sedimentary beds, gangue in ore veins, and in traprock zeolite occurrences.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1795
Help on Locality: Locality: World wide occurrences where marine evaporite beds occur. Often interbedded with halite. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek anhydros, meaning "waterless" (In contrast to Gypsum, which contains water).
Help on Name Pronunciation: Name Pronunciation: Anhydrite + Pronunciation Say ANHYDRITE
Help on Synonym: Synonym: Calcium Sulfate
  ICSD 16382
  PDF 37-1496

Anhydrite Image

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Comments: Several terminated groups of light blue anhydrite crystals in parallel growth.
Location: Naica. Chihuahua, Mexico. Scale: 9.5 x 8 x 6 cm.
© Isaias Casanova / IC Minerals

Anhydrite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9992:1:0.8916
Help on Cell Dimensions: Cell Dimensions: a = 6.991, b = 6.996, c = 6.238, Z = 4; V = 305.09 Den(Calc)= 2.96
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Amma
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.49(1), 2.849(0.35), 2.328(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) ( 0 1 1) ( 0 0 1) ( 1 0 1) ( 1 0 0)

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Physical Properties of Anhydrite

Help on Cleavage: Cleavage: {010} Perfect, {100} Perfect, {001} Good
Help on Color: Color: Colorless, White, Bluish white, Violet white, Dark gray.
Help on Density: Density: 2.96 - 2.98, Average = 2.97
Help on Diaphaneity: Diaphaneity: Transparent to Subtransparent 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 - Granular - Common texture observed in granite and other igneous rock.
Help on Habit: Habit: Plumose - "Mica-like" minerals forming aggregates of plume-like forms.
Help on Hardness: Hardness: 3.5 - Copper Penny
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous - Pearly
Help on Streak: Streak: white

Optical Properties of Anhydrite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.037 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.04 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1983,KPDmeas= 0.1976,KC= 0.1906
Ncalc = 1.56 - 1.57
Help on Optical Data: Optical Data: Biaxial (+), a=1.569-1.573, b=1.574-1.579, g=1.609-1.618, bire=0.0400-0.0450, 2V(Calc)=44, 2V(Meas)=36-45. Dispersion r < v.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.

Calculated Properties of Anhydrite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.97 gm/cc
note: Specific Gravity of Anhydrite =2.97 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0023895646
Boson Index = 0.9976104354
Help on Photoelectric: Photoelectric: PEAnhydrite = 5.03 barns/electron
U=PEAnhydrite x rElectron Density= 14.93 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Anhydrite is Not Radioactive

Anhydrite Classification

Help on  Dana Class: Dana Class: (28)Anhydrous Acid and Sulfates
  (28.03)(A++) XO4
  (28.03.02)Dana Group Anhydrite CaSO4 Amma 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 07.AD.30 07 - SULFATES (SELENATES, TELLURATES)
  07.A - Sulfates (selenates, etc.) without Additional Anions, without H2O
  07.AD -With only large cations
07.AD.30 Anhydrite CaSO4 Amma 2/m 2/m 2/m

Other Anhydrite Information

Help on See Also: See Also: Links to other databases for Anhydrite :
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 - Franklin Minerals(Palache)
8 - GeoScienceWorld
9 - Glendale Community College
10 - Google Images
11 - Google Scholar
12 - Handbook of Mineralogy (MinSocAm)
13 - Handbook of Mineralogy (UofA)
14 - MinDAT
15 - Mineral and Gemstone Kingdom
16 - Mineralienatlas (Deutsch)
17 - Online Mineral Museum
18 - QUT Mineral Atlas
19 - Ruff.Info
20 - Scandinavian mineral gallery
21 - University of Colorado - Mineral Structure Data
23 - theimage

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Dana No: Strunz No: 07.AD.30





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