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Gehlenite Mineral Data

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General Gehlenite Information

Help on Chemical  Formula: Chemical Formula: Ca2Al(AlSi)O7
Help on Composition: Composition: Molecular Weight = 274.20 gm
   Calcium   29.23 %  Ca   40.90 % CaO
   Aluminum  19.68 %  Al   37.18 % Al2O3
   Silicon   10.24 %  Si   21.91 % SiO2
   Oxygen    40.84 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca2Al2SiO7
Help on Environment: Environment: Contact metamorphic mineral in limestone.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1815
Help on Locality: Locality: Trentino, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the German chemist, A. F. Gehlen (1775-1815).
Help on Name Pronunciation: Name Pronunciation: Gehlenite + Pronunciation Say GEHLENITE
Help on Synonym: Synonym: ICSD 39921
  PDF 35-755
 

Gehlenite Image

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  Gehlenite

Comments: Crystalline massive gehlenite.
Location: Crestmore Quarry, Riverside County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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  Gehlenite

Comments: Contact area between vesuvianite (right) and gehlenite (left). Note the lamellae of clintonite included mainly in the gehlenite crystals (CanMin v. 41. p 1259).
Location: Skarns along the contact of a diorite intrusion at OravitÂļa, Banat, in Romania. Scale: Image size 2.7 mm.
© Canadian Mineralogist

Gehlenite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.6589
Help on Cell Dimensions: Cell Dimensions: a = 7.69, c = 5.067, Z = 2; V = 299.64 Den(Calc)= 3.04
Help on Crystal System: Crystal System: Tetragonal - Scalenohedral H-M Symbol (4 2m) Space Group: P 421m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 1.75(1), 2.85(1), 2.43(0.7),
 

Physical Properties of Gehlenite

Help on Cleavage: Cleavage: {001} Good
Help on Color: Color: Brown, Colorless, Greenish, Gray, Yellow.
Help on Density: Density: 2.9 - 3.07, Average = 2.98
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 5-6 - Between Apatite and Orthoclase
Help on Luster: Luster: Vitreous - Greasy
Help on Streak: Streak: white
 

Optical Properties of Gehlenite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.069 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= -0.049 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2188,KPDmeas= 0.2228,KC= 0.2084
Ncalc = 1.6 - 1.64
Help on Optical Data: Optical Data: Uniaxial (-), e=1.66, w=1.67, bire=0.0100.
 

Calculated Properties of Gehlenite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.02 gm/cc
note: Specific Gravity of Gehlenite =3.04 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0053740313
Boson Index = 0.9946259687
Help on Photoelectric: Photoelectric: PEGehlenite = 4.57 barns/electron
U=PEGehlenite x rElectron Density= 13.77 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Gehlenite is Not Radioactive
 

Gehlenite Classification

Help on  Dana Class: Dana Class: 55.04.01.02 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions
  (55.04)with cations in [8] and lower coordination
  (55.04.01)Melilite group
 
55.04.01.01 Akermanite Ca2MgSi2O7 P 421m 4 2m
 
55.04.01.02 Gehlenite Ca2Al(AlSi)O7 P 421m 4 2m
 
55.04.01.03 Melilite (Ca,Na)2(Al,Mg,Fe)(Si,Al)2O7 P 421m 4 2m
 
55.04.01.04 Okayamalite! Ca2B2SiO7 P 421m 4 2m
 
55.04.01.05 Alumoakermanite! (Ca,Na)2(Al,Mg,Fe)(Si2O7) P 421m 4 2m
Help on  Strunz Class: Strunz Class: 09.BB.10 09 - SILICATES (Germanates)
  09.B - Sorosilicates
  09.BB -Si2O7 groups, without non-tetrahedral anions;
 
09.BB.10 Akermanite Ca2MgSi2O7 P 421m 4 2m
 
09.BB.10 Cebollite Ca5Al2(SiO4)3(OH)4 Unk Ortho
 
09.BB.10 Gugiaite Ca2BeSi2O7 P 421m 4 2m
 
09.BB.10 Gehlenite Ca2Al(AlSi)O7 P 421m 4 2m
 
09.BB.10 Jeffreyite (Ca,Na)2(Be,Al)Si2(O,OH)7 C 2221 2 2 2
 
09.BB.10 Hardystonite Ca2ZnSi2O7 P 421m 4 2m
 
09.BB.10 Melilite (Ca,Na)2(Al,Mg,Fe)(Si,Al)2O7 P 421m 4 2m
 
09.BB.10 Okayamalite! Ca2B2SiO7 P 421m 4 2m
 

Other Gehlenite 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 Gehlenite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - University of Colorado - Mineral Structure Data
16 - WWW-MINCRYST

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

Gehlenite

Ca2Al(AlSi)O7
Dana No: 55.04.01.02 Strunz No: 09.BB.10
Locality:

 

Notes:

 

 
   
 


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