Spinel Mineral Data (original) (raw)

General Spinel Information

Chemical Formula:

MgAl2O4

Composition:

Molecular Weight = 142.27 gm

Magnesium 17.08 % Mg 28.33 % MgO

Aluminum 37.93 % Al 71.67 % Al2O3

Oxygen 44.98 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

MgAl2O4

Environment:

Metamorphic mineral found in limestone and dolomite marbles and very-low silica and alkali igneous rocks (e.g. peridotites).

IMA Status:

Valid Species (Pre-IMA) 1546

Locality:

Gem gravels of Sri Lanka and other notable locations. Link to MinDat.org Location Data.

Name Origin:

Of uncertain origin, possibly derived from Latin, spina, for "thorn" in allusion to sharply-pointed crystals.

Name Pronunciation:

Spinel

Synonym:

Balas ruby - Red

ICSD 79000

PDF 21-1152

Rubicelle

Ruby spinal

Spinel Image

Images:

	Spinel Comments: Spinel on white marble. Location: Mogok, Myanmar.Scale: 2.2 x 1.5 cm. © Fabre Minerals

Spinel Crystallography

Cell Dimensions:

a = 8.08, Z = 8; V = 527.51 Den(Calc)= 3.58

Crystal System:

Isometric - HexoctahedralH-M Symbol (4/m 3 2/m) Space Group: F d3m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/Io): 2.436(1), 2.021(0.7), 1.429(0.6),

Forms:

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Crystal Structure:

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Physical Properties of Spinel

Cleavage:

None

Color:

Colorless, Red, Blue, Green, Brown.

Density:

3.57 - 3.72, Average = 3.64

Diaphaneity:

Transparent to translucent to opaque

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

8 - Topaz

Luminescence:

Sometimes Fluorescent, Short UV=red, Long UV=red.

Luster:

Vitreous (Glassy)

Magnetism:

Nonmagnetic

Streak:

grayish white

Optical Properties of Spinel

Gladstone-Dale:

CI meas= -0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.035 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2123,KPDmeas= 0.2085,KC= 0.205
Ncalc = 1.73 - 1.76

Optical Data:

Isotropic, n=1.72-1.8.

Calculated Properties of Spinel

Electron Density:

Bulk Density (Electron Density)=3.59 gm/cc
note: Specific Gravity of Spinel =3.65 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PESpinel = 1.48 barns/electron
U=PESpinel x rElectron Density= 5.32 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Spinel is Not Radioactive

Spinel Classification

Dana Class:

07.02.01.01 (07)Multiple Oxides

(07.02)(A+ B++)2 X4 Spinel group

(07.02.01)(Aluminum subgroup)

07.02.01.01 Spinel MgAl2O4 F d3m 4/m 3 2/m

07.02.01.02 Galaxite (Mn,Mg)(Al,Fe)2O4 F d3m 4/m 3 2/m

07.02.01.03 Hercynite FeAl2O4 F d3m 4/m 3 2/m

07.02.01.04 Gahnite ZnAl2O4 F d3m 4/m 3 2/m

Strunz Class:

04.BB.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.B - Metal:Oxygen = 3:4 and similar

04.BB -With only medium-sized cations

04.BB.05 Cochromite (Co,Ni,Fe)(Cr,Al)2O4 F d3m 4/m 3 2/m

04.BB.05 Filipstadite (Mn,Mg)4SbFeO8 pseudo ISO 2/m 2/m 2/m

04.BB.05 Magnetite FeFe2O4 F d3m 4/m 3 2/m

04.BB.05 Gahnite ZnAl2O4 F d3m 4/m 3 2/m

04.BB.05 Chromite FeCr2O4 F d3m 4/m 3 2/m

04.BB.05 Galaxite (Mn,Mg)(Al,Fe)2O4 F d3m 4/m 3 2/m

04.BB.05 Cuprospinel (Cu,Mg)Fe2O4 F d3m 4/m 3 2/m

04.BB.05 Donathite? (Fe,Mg)(Cr,Fe)2O4 P 4/nnm 4/m 2/m 2/m

04.BB.05 Brunogeierite (Ge,Fe)Fe2O4 F d3m 4/m 3 2/m

04.BB.05 Coulsonite FeV2O4 F d3m 4/m 3 2/m

04.BB.05 Hercynite FeAl2O4 F d3m 4/m 3 2/m

04.BB.05 Franklinite (Zn,Mn,Fe)(Fe,Mn)2O4 F d3m 4/m 3 2/m

04.BB.05 Jacobsite (Mn,Fe,Mg)(Fe,Mn)2O4 F d3m 4/m 3 2/m

04.BB.05 Magnesiochromite MgCr2O4 F d3m 4/m 3 2/m

04.BB.05 Magnesioferrite MgFe2O4 F d3m 4/m 3 2/m

04.BB.05 Magnesiocoulsonite MgV2O4 F d3m 4/m 3 2/m

04.BB.05 Manganochromite (Mn,Fe)(Cr,V)2O4 F d3m 4/m 3 2/m

04.BB.05 Qandilite (Mg,Fe)2(Ti,Fe,Al)O4 F d3m 4/m 3 2/m

04.BB.05 Nichromite (Ni,Co,Fe)(Cr,Fe,Al)2O4 F d3m 4/m 3 2/m

04.BB.05 Spinel MgAl2O4 F d3m 4/m 3 2/m

04.BB.05 Ulvospinel TiFe2O4 F d3m 4/m 3 2/m

04.BB.05 Zincochromite ZnCr2O4 F d3m 4/m 3 2/m

04.BB.05 Trevorite NiFe2O4 F d3m 4/m 3 2/m

04.BB.05 Vuorelainenite (Mn,Fe)(V,Cr)2O4 F d3m 4/m 3 2/m

Other Spinel Information

References:

NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990;Dana8) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

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

Spinel

MgAl2O4
Dana No: 07.02.01.01 Strunz No: 04.BB.05
Locality:

Notes: