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Crossite Mineral Data

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General Crossite Information

Help on Chemical  Formula: Chemical Formula: Na2(Mg,Fe++)3(Al,Fe+++)2Si8O22(OH)2
Help on Composition: Composition: Molecular Weight = 795.32 gm
   Sodium      5.78 %  Na    7.79 % Na2O
   Magnesium   6.11 %  Mg   10.14 % MgO
   Aluminum    2.54 %  Al    4.81 % Al2O3
   Iron        8.78 %  Fe    9.03 % FeO /  2.51 % Fe2O3
   Silicon    28.25 %  Si   60.44 % SiO2
   Hydrogen    0.25 %  H     2.27 % H2O
   Oxygen     48.28 %  O
             ______        ______ 
             100.00 %       96.98 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na2Mg2Fe2+Al0.75Fe3+0.25(Si8O22)(OH)2
Help on Environment: Environment: High pressure, low temperature metamorphic mineral. Discredited by IMA amphibole subcommittee (now glaucophane or ferroglaucophane or magnesioriebeckite or riebeckite).
Help on IMA Status: IMA Status: Discredited IMA 1997 - Valid Species (Pre-IMA) 1894
Help on Locality: Locality: Berkeley, Conta Costa Co., USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named in 1894 for Charles Whitman Cross, (1854-1949), geologist, United States Geological Survey.
Help on Synonym: Synonym: Discredited
  ICSD 27459
  PDF 20-376
 

Crossite Image

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  Crossite

Comments: Black prismatic crystal clusters of crossite.
Location: near Valley Ford, Sonoma County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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  Crossite

Comments: Long metallic, black, prismatic crystals or crossite on matrix.
Location: Webbing, Lammertal, Salzburg, Austria. Scale: Picture size 2.5 mm.
© Tom Loomis / Dakota Matrix

Crossite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5387:1:0.2969
Help on Cell Dimensions: Cell Dimensions: a = 9.647, b = 17.905, c = 5.316, Z = 2; beta = 103.6° V = 892.48 Den(Calc)= 2.96
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 8.31(1), 3.08(0.7), 2.71(0.4),2.53(0.2), 3.4(0.2), 4.48(0.2), 4.87(0.2), 8.95(0.1),
 

Physical Properties of Crossite

Help on Cleavage: Cleavage: {110} Perfect, {010} Good
Help on Color: Color: Blue, Gray, Gray blue.
Help on Density: Density: 3.16
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Brittle - Uneven - Very brittle fracture producing uneven fragments.
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white
 

Optical Properties of Crossite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.02 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.089 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2214,KPDmeas= 0.2074,KC= 0.2033
Ncalc = 1.6 - 1.64
Help on Optical Data: Optical Data: Biaxial (-), a=1.64-1.659, b=1.645-1.666, g=1.652-1.67, bire=0.0110-0.0120, 2V(Calc)=72-82, 2V(Meas)=12-65. Dispersion very strong, r > v.
Help on Pleochroism (x): Pleochroism (x): wine yellow, pale yellow, colorless, or pale mauve blue.
Help on Pleochroism (y): Pleochroism (y): blue, prussian blue, purplish blue, or deep blue.
Help on Pleochroism (z): Pleochroism (z): grayish violet, violet, blue, or deep mauve blue.
 

Calculated Properties of Crossite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.13 gm/cc
note: Specific Gravity of Crossite =3.16 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PECrossite = 3.98 barns/electron
U=PECrossite x rElectron Density= 12.48 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Crossite is Not Radioactive
 

Crossite Classification

Help on  Dana Class: Dana Class: 66.01.03c.03 (66)Inosilicate Double-Width Unbranched Chains, W=2
  (66.01)with P=2 amphibole configuration
  (66.01.03c)Group 4, the sodic amphiboles
 
66.01.03c.01 Glaucophane []Na2(Mg3Al2)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.02 Ferroglaucophane []Na2(Fe3Al2)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.03 Crossite? Na2(Mg,Fe)3(Al,Fe)2Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.04 Magnesioriebeckite []Na2[(Mg,Fe)3Fe2]Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.05 Riebeckite []Na2(Fe3Fe2)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.06 Eckermannite NaNa2(Mg4Al)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.07 Ferro-eckermannite NaNa2(Fe4Al)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.08 Magnesio-arfvedsonite NaNa2(Mg4Fe)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.09 Arfvedsonite NaNa2(Fe4Fe)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.09a Fluoro-magnesio-arfvedsonite! NaNa2(Mg,Fe)4Fe[Si8O22](F,OH)2 C 2/m 2/m
 
66.01.03c.09b Potassicarfvedsonite! KNa2Fe4FeSi8O22(OH)2 C 2/m 2/m
 
66.01.03c.10 Kozulite NaNa2Mn4(Fe,Al)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.11 Nyboite NaNa2(Mg3Al2)Si7AlO22(OH)2 C 2/m 2/m
 
66.01.03c.11a Ferronyboite! NaNa2(Fe)3Al2(Si7Al)O22(OH)2 C 2/m 2/m
 
66.01.03c.11b Ferric-ferronyboite! NaNa2(Fe)3(Fe)2(Si7Al)O22(OH)2 C 2/m 2/m
 
66.01.03c.11c Fluoronyboite! NaNa2(Al2Mg3)(Si7Al)O22(F,OH)2 C 2/m 2/m
 
66.01.03c.12 Leakeite NaNa2(Mg2Fe2Li)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.12a Ferroleakeite! NaNa2(Fe)3(Fe)2Li(Si8O22)(OH)2 C 2/m 2/m
 
66.01.03c.12b Potassicleakeite! KNa2Mg2Fe2LiSi8O22(OH)2 C 2/m 2/m
 
66.01.03c.13 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 C 2/m 2/m
 
66.01.03c.14 Ungarettiite NaNa2(Mn2Mn3)Si8O22O2 C 2/m 2/m
 
66.01.03c.15 Fluoro-ferroleakeite NaNa2(Fe2Fe2Li)Si8O22F2 C 2/m 2/m
 
66.01.03c.16 Obertiite! NaNa2(Mg3FeTi)Si8O22(O,F,OH)2 C 2/m 2/m
 
66.01.03c.17 Dellaventuraite! NaNa2(Mg2,Mn,Li,Ti)Si8O22O2 C 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.DE.25 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DE -Inosilicates with 2-periodic double chains, Si4O11; amphibole family
 
09.DE.25 Arfvedsonite NaNa2(Fe4Fe)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Ferroglaucophane []Na2(Fe3Al2)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Crossite? Na2(Mg,Fe)3(Al,Fe)2Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Eckermannite NaNa2(Mg4Al)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Glaucophane []Na2(Mg3Al2)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Fluoro-ferroleakeite NaNa2(Fe2Fe2Li)Si8O22F2 C 2/m 2/m
 
09.DE.25 Ferro-eckermannite NaNa2(Fe4Al)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Ferroleakeite! NaNa2(Fe)3(Fe)2Li(Si8O22)(OH)2 C 2/m 2/m
 
09.DE.25 Ferronyboite! NaNa2(Fe)3Al2(Si7Al)O22(OH)2 C 2/m 2/m
 
09.DE.25 Ferric-ferronyboite! NaNa2(Fe)3(Fe)2(Si7Al)O22(OH)2 C 2/m 2/m
 
09.DE.25 Obertiite! NaNa2(Mg3FeTi)Si8O22(O,F,OH)2 C 2/m 2/m
 
09.DE.25 Nyboite NaNa2(Mg3Al2)Si7AlO22(OH)2 C 2/m 2/m
 
09.DE.25 Magnesioriebeckite []Na2[(Mg,Fe)3Fe2]Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Kozulite NaNa2Mn4(Fe,Al)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 C 2/m 2/m
 
09.DE.25 Leakeite NaNa2(Mg2Fe2Li)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Magnesio-arfvedsonite NaNa2(Mg4Fe)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Ungarettiite NaNa2(Mn2Mn3)Si8O22O2 C 2/m 2/m
 
09.DE.25 Riebeckite []Na2(Fe3Fe2)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Potassicleakeite! KNa2Mg2Fe2LiSi8O22(OH)2 C 2/m 2/m
 
09.DE.25 Fluoronyboite! NaNa2(Al2Mg3)(Si7Al)O22(F,OH)2 C 2/m 2/m
 
09.DE.25 Fluoro-magnesio-arfvedsonite! NaNa2(Mg,Fe)4Fe[Si8O22](F,OH)2 C 2/m 2/m
 
09.DE.25 Potassicarfvedsonite! KNa2Fe4FeSi8O22(OH)2 C 2/m 2/m
 
09.DE.25 Dellaventuraite! NaNa2(Mg2,Mn,Li,Ti)Si8O22O2 C 2/m 2/m
 

Other Crossite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana)
Help on See Also: See Also: Links to other databases for Crossite :
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 (UofA)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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Crossite

Na2(Mg,Fe++)3(Al,Fe+++)2Si8O22(OH)2
Dana No: 66.01.03c.03 Strunz No: 09.DE.25
Locality:

 

Notes:

 

 
   
 


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