Giniite Mineral Data

General Giniite Information

Chemical Formula:

Fe++Fe+++4(PO4)4(OH)2•2(H2O)

Composition:

Molecular Weight = 729.17 gm

Iron 38.30 % Fe 9.85 % FeO / 43.80 % Fe₂O₃

Phosphorus 16.99 % P 38.93 % P₂O₅

Hydrogen 0.83 % H 7.41 % H₂O

Oxygen 43.88 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Fe³⁺₄(PO₄)₄(OH)₂•2(H₂O)

Environment:

In a pegmatite.

IMA Status:

Approved IMA 1980

Locality:

Sandamab, near Usakos, Namibia. Link to MinDat.org Location Data.

Name Origin:

Named by Paul Keller for his wife, Gini Keller.

Name Pronunciation:

Giniite

Giniite Image

Images:

Giniite

Comments: Dark greenish black crystals of giniite on matrix.
Location: Sandamab, Usakos, Namibia. Scale: Picture size 1.3 mm.
© Thomas Witzke / Abraxas-Verlag

Giniite Crystallography

Axial Ratios:

a:b:c =2.7664:1:2.0095

Cell Dimensions:

a = 14.253, b = 5.152, c = 10.353, Z = 2; beta = 111.3° V = 708.31 Den(Calc)= 3.42

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2/a

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

By Intensity(I/I_o): 3.36(1), 2.04(0.7), 3.2(0.7),

Physical Properties of Giniite

Cleavage:

None

Color:

Blackish brown, Black, Blackish green.

Density:

3.41

Diaphaneity:

Translucent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Crystalline - Fine - Occurs as well-formed fine sized crystals.

Hardness:

3-4 - Calcite-Fluorite

Luster:

Vitreous - Greasy

Streak:

olive green

Optical Properties of Giniite

Gladstone-Dale:

CI meas= 0.076 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.079 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2329,KPDmeas= 0.2336,KC= 0.2529
Ncalc = 1.86 - 1.87

Optical Data:

Biaxial (-), a=1.775, b=1.803, g=1.812, bire=0.0370, 2V(Calc)=58, 2V(Meas)=55.

Pleochroism (x):

light brown.

Pleochroism (y):

dark brown.

Pleochroism (z):

dark blue green.

Calculated Properties of Giniite

Electron Density:

Bulk Density (Electron Density)=3.33 gm/cc
note: Specific Gravity of Giniite =3.41 gm/cc.

Fermion Index:

Fermion Index = 0.008330457
Boson Index = 0.991669543

Photoelectric:

PE_Giniite= 12.26 barns/electron
U=PE_Giniite x rElectron Density= 40.81 barns/cc.

Radioactivity:

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

Giniite Classification

Dana Class:

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

(42.11)where (AB)4 (XO4)3 Zq ï¿½ x(H2O)

(42.11.07)Dana Group

42.11.07.01 Giniite FeFe4(PO4)4(OH)2•2(H2O) P 2/a 2/m

Strunz Class:

08.DB.50 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DB -With only medium-sized cations, (OH, etc.):RO4 < 1:1

08.DB.50 Giniite FeFe4(PO4)4(OH)2•2(H2O) P 2/a 2/m

Other Giniite Information

References:

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

See Also:

Links to other databases for Giniite :
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

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

Giniite

Fe++Fe+++4(PO4)4(OH)2•2(H2O)
Dana No: 42.11.07.01 Strunz No: 08.DB.50
Locality:

Notes:

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