General Chromdravite Information![]() NaMg3(Cr,Fe+++)6(BO3)3Si6O18(OH)4 |
![]() Molecular Weight = 1,114.61 gm |
|
Sodium 2.06 % Na 2.78 % Na2O |
|
Magnesium 6.54 % Mg 10.85 % MgO |
|
Chromium 20.99 % Cr 27.45 % CrO |
|
Iron 7.52 % Fe 10.75 % Fe2O3 |
|
Silicon 15.12 % Si 32.34 % SiO2 |
|
Boron 2.91 % B 9.37 % B2O3 |
|
Hydrogen 0.36 % H 3.23 % H2O |
|
Oxygen 44.50 % O |
|
______ ______ |
|
100.00 % 96.77 % = TOTAL OXIDE |
![]() NaMg3Cr4.5Fe3+1.5(BO3)3Si6O18(OH)4 |
![]() Magnesium and chromium-bearing tourmaline in micaceous metasomatites. |
![]() Approved IMA 1983 (Dana # Changed) |
![]() Onezhkii depression, central Karelia, Russia. Link to MinDat.org Location Data. |
![]() Named for the compositional relationship to dravite. |
![]() Chromdravite - (61.3.1.11) |
|
Tourmaline |
| | Chromdravite Image
|
![]()
|
Chromdravite Crystallography![]() a:c = 1:0.45127 |
![]() a = 16.11, c = 7.27, Z = 3; V = 1,634.02 Den(Calc)= 3.40 |
![]() Trigonal - Ditrigonal PyramidalH-M Symbol (3m) Space Group: R 3m |
![]() By Intensity(I/Io): 2.62(1), 3.04(0.75), 3.58(0.75), |
|
![]()
Mouse
|
| Physical Properties of Chromdravite![]() None |
![]() Greenish black, Dark green. |
![]() 3.4 |
![]() Translucent to Opaque |
![]() Blocky - Crystal shape tends to be equant (e.g. feldspars). |
![]() Striated - Parallel lines on crystal surface or cleavage face. |
![]() 7-7.5 - Quartz-Garnet |
![]() Non-fluorescent. |
![]() Vitreous - Resinous |
![]() greenish gray |
| Optical Properties of Chromdravite![]() yellow green. |
![]() dark green. |
![]() CI meas= -0.029 (Excellent) - where the CI = (1-KPDmeas/KC) |
CI calc= -0.029 (Excellent) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2209,KPDmeas= 0.2209,KC= 0.2147 Ncalc = 1.73 ![]() Uniaxial (-), e=1.722-1.724, w=1.778-1.78, bire=0.0560. |
| Calculated Properties of Chromdravite![]() Bulk Density (Electron Density)=3.32 gm/cc |
note: Specific Gravity of Chromdravite =3.40 gm/cc. ![]() Fermion Index = 0.04 |
Boson Index = 0.96 ![]() PEChromdravite = 7.71 barns/electron |
U=PEChromdravite x rElectron Density= 25.62 barns/cc. ![]() GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Chromdravite is Not Radioactive | Chromdravite Classification![]() 61.03e.01.11 (61)Cyclosilicate Six-Membered Rings |
|
(61.03e)with borate groups (Sodic Tourmaline Subgroup) |
|
(61.03e.01)Schorl Subgroup |
|
|
|
|
|
![]() 09.CK.05 09 - SILICATES (Germanates) |
|
09.C - Cyclosilicates |
|
09.CK -[Si6O18]12- 6-membered single rings, with insular complex anions |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Other Chromdravite Information![]() NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8) |
![]() Links to other databases for Chromdravite : |
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 Search for Chromdravite using: Visit our Advertisers for Chromdravite : A Bijoux Google Search for ChromdraviteAdam's Minerals Google Search for Chromdravite Cape Minerals Google Search for Chromdravite Dakota Matrix Minerals Google Search for Chromdravite Excalibur Mineral Corp. Google Search for Chromdravite Exceptional Minerals Google Search for Chromdravite John Betts Fine Minerals Search for Chromdravite McDougall Minerals Google Search for Chromdravite Mineral News Website Link Rock and Mineral Shows Google Search for Chromdravite Weinrich Minerals, Inc. Google Search for Chromdravite Ask about Chromdravite here : Print or Cut-and-Paste your Chromdravite Specimen Label here :
| |
|
| |