General Derbylite Information Chemical Formula: |
(Fe+++,Fe++,Ti)7Sb+++O13(OH) |
Composition: |
Molecular Weight = 721.74 gm |
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Titanium 13.27 % Ti 22.13 % TiO2 |
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Iron 38.69 % Fe 19.91 % FeO / 33.19 % Fe2O3 |
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Antimony 16.87 % Sb 20.19 % Sb2O3 |
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Hydrogen 0.14 % H 1.25 % H2O |
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Oxygen 31.03 % O |
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100.00 % 96.67 % = TOTAL OXIDE |
Empirical Formula: |
Fe3+3Fe2+2Ti2SbO13(OH) |
Environment: |
In cinnaber-bearing placer gravels. |
IMA Status: |
Valid Species (Pre-IMA) 1897 |
Locality: |
Tripuhy, Ouro Preto, Minas Gerais, Brazil. Link to MinDat.org Location Data. |
Name Origin: |
Named after the American Geologist Orville A. Derby 1851 - 1915 founder of the Brazilian Geological Survey. |
Name Pronunciation: |
Derbylite + Pronunciation |
Synonym: |
ICSD 9825 |
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PDF 35-599 |
| | Derbylite Image
Images:
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Derbylite Crystallography Axial Ratios: |
a:b:c =0.499:1:0.3464 |
Cell Dimensions: |
a = 7.16, b = 14.347, c = 4.97, Z = 2; beta = 104.61° V = 494.03 Den(Calc)= 4.85 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 21/m |
X Ray Diffraction: |
By Intensity(I/Io): 2.853(1), 2.674(0.73), 3.186(0.43), |
Crystal Structure:
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Mouse
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| Physical Properties of Derbylite Cleavage: |
None |
Color: |
Pitch black, Black, Dark brown. |
Density: |
4.5 - 4.6, Average = 4.55 |
Diaphaneity: |
Opaque |
Fracture: |
Brittle - Generally displayed by glasses and most non-metallic minerals. |
Habit: |
Granular - Generally occurs as anhedral to subhedral crystals in matrix. |
Habit: |
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline). |
Hardness: |
5 - Apatite |
Luster: |
Resinous - Metallic |
Streak: |
brownish black |
| Optical Properties of Derbylite Gladstone-Dale: |
CI meas= -0.178 (Poor) - where the CI = (1-KPDmeas/KC) |
CI calc= -0.105 (Poor) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.3031,KPDmeas= 0.3231,KC= 0.2742 Ncalc = 2.23 - 2.33 Optical Data: |
Biaxial (+), a=2.45, b=2.45, g=2.51, bire=0.0600, 2V(Calc)=0, 2V(Meas)=~0. |
RL Color: |
Gray with bluish green internal reflections. |
Reflectivity |
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| Calculated Properties of Derbylite Electron Density: |
Bulk Density (Electron Density)=4.54 gm/cc |
note: Specific Gravity of Derbylite =4.85 gm/cc. Fermion Index: |
Fermion Index = 0.02 |
Boson Index = 0.98 Photoelectric: |
PEDerbylite = 67.25 barns/electron |
U=PEDerbylite x rElectron Density= 305.47 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Derbylite is Not Radioactive | Derbylite Classification Dana Class: |
46.02.03.02 (46)Basic or Halogen-Containing Antimonites, Arsenites and Phosphites |
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(46.02)with miscellaneous formulae |
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(46.02.03)Derbylite Group |
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Strunz Class: |
04.JB.55 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate |
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04.J - Arsenites, Antimonites, Bismuthites, Sulfites, |
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04.JB -Arsenites, antimonites, bismuthites; with additional anions, without H2O |
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| Other Derbylite Information References: |
NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(AntBidBlaNic3) |
See Also: |
Links to other databases for Derbylite : |
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 - WWW-MINCRYST Search for Derbylite using: Visit our Advertisers for Derbylite : A Bijoux Google Search for DerbyliteAdam's Minerals Google Search for Derbylite Cape Minerals Google Search for Derbylite Dakota Matrix Minerals Google Search for Derbylite Excalibur Mineral Corp. Google Search for Derbylite Exceptional Minerals Google Search for Derbylite John Betts Fine Minerals Search for Derbylite McDougall Minerals Google Search for Derbylite Mineral News Website Link Rock and Mineral Shows Google Search for Derbylite Weinrich Minerals, Inc. Google Search for Derbylite Ask about Derbylite here : Print or Cut-and-Paste your Derbylite Specimen Label here :
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