Mineralogy Database

Corundum Mineral Data

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General Corundum Information

Help on Chemical  Formula: Chemical Formula: Al2O3
Help on Composition: Composition: Molecular Weight = 101.96 gm
   Aluminum  52.93 %  Al  100.00 % Al2O3
   Oxygen    47.07 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: (Al2O3)
Help on Environment: Environment: Contact and regionally metamorphosed rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) Prehistoric
Help on Locality: Locality: Tchainit and Yakutia, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Probably derived from the Sanskrit, kuruvinda, meaning "ruby."
Help on Name Pronunciation: Name Pronunciation: Corundum Say CORUNDUM
Help on Synonym: Synonym: ICSD 31545
  Leucosapphire - colorless
  PDF 43-1484
  Ruby - red
  Sapphire - blue

Corundum Image

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Comments: corundum (variety Sapphire).
Location: Miass, Urals, Russia. Scale: 10 x 8 cm.
© Fabre Minerals

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  Zincohogbomite-2N2S   Corundum

Comments: Thin-Section (Plane Polarized Light) of a brown, twinned zincohögbomite-2N2S crystal with blue corundum.
Location: Mikro-Lakka Emery deposit, Kerketeas Mt, Sámos Island, Aegean Islands Department, Greece. Scale: Picture size 1.1 mm.
© Thomas Witzke / Abraxas-Verlag

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Comments: Bright red ruby corundum crystals in white marble matrix.
Location: Jagdalak (Jagdalek; Jagdalik) Ruby Mine, Sorobi District, Konar (Kunar; Konarh; Konarha; Nuristan) Province, Afghanistan. Scale: 4x3.5x3 cm.
© John Betts - Fine Minerals

Corundum Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:2.72995
Help on Cell Dimensions: Cell Dimensions: a = 4.751, c = 12.97, Z = 6; V = 253.54 Den(Calc)= 4.01
Help on Crystal System: Crystal System: Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.085(1), 2.552(0.9), 1.601(0.8),
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: ( 1 1 4) ( 2 0 1) ( 1 0 2) ( 1 0 1) ( 0 0 1)

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Physical Properties of Corundum

Help on Cleavage: Cleavage: None
Help on Color: Color: Blue, Red, Yellow, Brown, Gray.
Help on Density: Density: 4 - 4.1, Average = 4.05
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Tough - Difficult to break apart as shown by fibrous minerals and most metals.
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
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: 9 - Corundum
Help on Luminescence: Luminescence: Sometimes Fluorescent, Long UV=red.
Help on Luster: Luster: Vitreous (Glassy)
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: none

Optical Properties of Corundum

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.089 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.08 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1905,KPDmeas= 0.1886,KC= 0.207
Ncalc = 1.83 - 1.85
Help on Optical Data: Optical Data: Uniaxial (-), e=1.76, w=1.768, bire=0.0080.

Calculated Properties of Corundum

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.93 gm/cc
note: Specific Gravity of Corundum =4.01 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0002259597
Boson Index = 0.9997740403
Help on Photoelectric: Photoelectric: PECorundum = 1.54 barns/electron
U=PECorundum x rElectron Density= 6.08 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Corundum is Not Radioactive

Corundum Classification

Help on  Dana Class: Dana Class: (04)Simple Oxides
  (04.03)with a cation charge of 3+ (A+++2 O3)
  (04.03.01)Corundum-Hematite group (Rhombohedral: R-3c) Corundum Al2O3 R 3c 3 2/m Hematite Fe2O3 R 3c 3 2/m Eskolaite Cr2O3 R 3c 3 2/m Karelianite V2O3 R 3c 3 2/m Tistarite! Ti2O3 R 3c 3 2/m
Help on  Strunz Class: Strunz Class: 04.CB.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.C - Metal:Oxygen = 2:3, 3:5, and Similar
  04.CB -With medium-sized cations
04.CB.05 Auroantimonate* AuSbO3 Ortho ? Ortho
04.CB.05 Geikielite MgTiO3 R 3 3
04.CB.05 Brizziite-III NaSbO3 R 3 3
04.CB.05 Brizziite-VII NaSbO3 R 3 3
04.CB.05 Ecandrewsite (Zn,Fe,Mn)TiO3 R 3 3
04.CB.05 Corundum Al2O3 R 3c 3 2/m
04.CB.05 Eskolaite Cr2O3 R 3c 3 2/m
04.CB.05 Hematite Fe2O3 R 3c 3 2/m
04.CB.05 Karelianite V2O3 R 3c 3 2/m
04.CB.05 Ilmenite FeTiO3 R 3 3
04.CB.05 Melanostibite Mn(Sb,Fe)O3 R 3 3
04.CB.05 Pyrophanite MnTiO3 R 3 3
04.CB.05 Romanite* (Fe,U,Pb)2(Ti,Fe)O4 Trig ? Trig
04.CB.05 Tistarite! Ti2O3 R 3c 3 2/m

Other Corundum Information

Help on References: References: NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Sinkankas66)
Help on See Also: See Also: Links to other databases for Corundum :
1 - Alkali-Nuts(English)
2 - Am. Min. Crystal Structure Database
3 - Amethyst Galleries' Mineral Gallery
4 - Athena
5 - CalTech Mineral Spectroscopy
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 - NSDL Reciprocal Net (JAVA)
18 - Online Mineral Museum
19 - Philatelic Mineralogy
20 - QUT Mineral Atlas
21 - Ruff.Info
22 - Scandinavian mineral gallery
23 - Tradeshop.com - The Rainbow of Gems
24 - UCLA - Petrography Thin-Sections
25 - University of Colorado - Mineral Structure Data
26 - University of Texas at Austin

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Dana No: Strunz No: 04.CB.05





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