Gormanite Mineral Data

General Gormanite Information

Chemical Formula:

Fe++3Al4(PO4)4(OH)6•2(H2O)

Composition:

Molecular Weight = 793.43 gm

Aluminum 13.60 % Al 25.70 % Al₂O₃

Iron 21.12 % Fe 27.17 % FeO

Phosphorus 15.62 % P 35.78 % P₂O₅

Hydrogen 1.27 % H 11.35 % H₂O

Oxygen 48.40 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺₃Al₄(PO₄)₄(OH)₆•2(H₂O)

Environment:

Phosphate ironstones. Forms a series with souzalite.

IMA Status:

Approved IMA 1981

Locality:

Rapid Creek and Big Fish area, Yukon Territory, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for Donald Herbert Groman (1922-), University of Toronto, Canada.

Name Pronunciation:

Gormanite + Pronunciation

Synonym:

IMA1977-030

Gormanite Image

Images:

Gormanite

Comments: Elongated, dark bluish green, fibrous crystals of gormanite and quartz on a matrix of quartz and water clear apatite crystals.
Location: Big Fish River, Yukon Territory, Canada. Scale: 4.8 x 3.8 cm.
© John Veevaert

Images:

Gormanite

Comments: Dark green, velvety mass of gormanite crystals on matrix.
Location: Rapid Creek, Yukon Territory, Canada. Scale: 3 x 4.5 cm.
© Dave Barthelmy

Gormanite Crystallography

Axial Ratios:

a:b:c =2.3072:1:2.6555

Cell Dimensions:

a = 11.79, b = 5.11, c = 13.57, Z = 2; alpha = 90.83°, beta = 99.25°, gamma = 90.082° V = 806.83 Den(Calc)= 3.27

Crystal System:

Triclinic Space Group: P1,P 1

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

By Intensity(I/I_o): 3.395(1), 2.554(0.9), 2.925(0.8),

Physical Properties of Gormanite

Cleavage:

{001} Indistinct

Color:

Blue green.

Density:

3.13

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

4-5 - Fluorite-Apatite

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

pale green

Optical Properties of Gormanite

Gladstone-Dale:

CI meas= 0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.055 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1969,KPDmeas= 0.2058,KC= 0.2084
Ncalc = 1.65 - 1.68

Optical Data:

Biaxial (-), a=1.619, b=1.653, g=1.66, bire=0.0410, 2V(Calc)=48, 2V(Meas)=53.

Pleochroism (x):

colorless.

Pleochroism (y):

blue.

Pleochroism (z):

colorless.

Calculated Properties of Gormanite

Electron Density:

Bulk Density (Electron Density)=3.09 gm/cc
note: Specific Gravity of Gormanite =3.13 gm/cc.

Fermion Index:

Fermion Index = 0.0047108218
Boson Index = 0.9952891782

Photoelectric:

PE_Gormanite= 7.39 barns/electron
U=PE_Gormanite x rElectron Density= 22.85 barns/cc.

Radioactivity:

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

Gormanite Classification

Dana Class:

42.09.02.02 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.09)where (A)3 (XO4)2 Zq ï¿½ x(H2O)

(42.09.02)Souzalite Group

42.09.02.01 Souzalite (Mg,Fe)3(Al,Fe)4(PO4)4(OH)6•2(H2O) P1,P 1 Tri

42.09.02.02 Gormanite Fe3Al4(PO4)4(OH)6•2(H2O) P1,P 1 Tri

42.09.02.03 Andyrobertsite! KCdCu5(AsO4)4[As(OH)2O2]•2(H2O) P 2₁/m 2/m

42.09.02.04 Calcioandyrobertsite-1M! KCaCu5(AsO4)4[As(OH)2O2]•2(H2O) P 2₁/m 2/m

42.09.02.05 Calcioandyrobertsite-2O! KCaCu5(AsO4)4[As(OH)2O2]•2(H2O) P nma 2/m 2/m 2/m

Strunz Class:

08.DC.45 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DC -With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1

08.DC.45 Gormanite Fe3Al4(PO4)4(OH)6•2(H2O) P1,P 1 Tri

08.DC.45 Souzalite (Mg,Fe)3(Al,Fe)4(PO4)4(OH)6•2(H2O) P1,P 1 Tri

Other Gormanite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Gormanite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info

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

Gormanite

Fe++3Al4(PO4)4(OH)6•2(H2O)
Dana No: 42.09.02.02 Strunz No: 08.DC.45
Locality:

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