Melliniite Mineral Data

General Melliniite Information

Chemical Formula:

(Ni,Fe)4P

Composition:

Molecular Weight = 259.69 gm

Iron 35.27 % Fe

Cobalt 0.23 % Co

Nickel 51.98 % Ni

Phosphorus 12.52 % P

______

100.00 %

Empirical Formula:

Ni_2.3Fe²⁺_1.64Co_0.01P_1.05

Environment:

Found in an acapulcoite, a primitive achondrite meteorite. New structure type.

IMA Status:

Approved IMA 2005 (Dana # Added)

Locality:

Acapulcoite achondrite ‘Northwest Africa 1054’. Link to MinDat.org Location Data.

Name Origin:

Named in honor of Marcello Mellini, Full Professor of Mineralogy at the University of Siena, in recognition of his contributions to the development of the study of meteorites in Ita ly.

Synonym:

IMA2005-027

Melliniite Image

Images:

Melliniite Kamacite

Comments: Reflected-light image displaying an anhedral fragment of creamy-yellowish melliniite(1) associated with kamacite (2). AmMin, v91, p453.
Location: Northwest Africa 1054 acapulcoite. Scale: See Image.
© American Mineralogist

Images:

Melliniite Nickelphosphide

Comments: Reflected light image of creamy-yellowish melliniite (1) and nickelphosphide (3). AmMin, v91, p453.
Location: Northwest Africa 1054 acapulcoite. Scale: See Image.
© American Mineralogist

Melliniite Crystallography

Cell Dimensions:

a = 6.025, Z = 4; V = 218.71 Den(Calc)= 7.89

Crystal System:

Isometric - TetartoidalH-M Symbol (2 3) Space Group: P 2₁3

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

By Intensity(I/I_o): 2.005(1), 1.906(0.6), 1.816(0.2),1.119(0.15), 1.182(0.15), 2.694(0.15), 1.348(0.1), 1.42(0.1),

Crystal Structure:

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Pratesi G , Bindi L , Moggi-Cecchi V , American Mineralogist , 91 (2006) p.451-454, Icosahedral coordination of phosphorus in the crystal structure of melliniite,, a new phosphide mineral from the Northwest Africa 1054 acapulcoite

Physical Properties of Melliniite

Color:

Creamy yellow.

Diaphaneity:

Opaque

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Hardness:

8-8.5 - Between Topaz and Chrysoberyl

Luster:

Metallic

Streak:

gray

Optical Properties of Melliniite

RL Anisotrophism:

None.

RL Bireflectance:

None.

RL Color:

Cream yellowish with no internal reflections.

RL Pleochroism:

None.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Melliniite in Air**
λ	R	∑ R(λ)
470 nm	60.50
548 nm	50.40
587 nm	52.50
650 nm	55.90

**Calculated Relative Intensity Colors of Melliniite in Air**
Relative Intensity	0%	20%	40%	60%	80%	100%	120%	140%	160%	170%
R

Calculated Properties of Melliniite

Electron Density:

Bulk Density (Electron Density)=7.48 gm/cc
note: Specific Gravity of Melliniite =7.89 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Melliniite= 32.59 barns/electron
U=PE_Melliniite x rElectron Density= 243.68 barns/cc.

Radioactivity:

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

Melliniite Classification

Dana Class:

01.01.21.05 (01)Native Elements

(01.01)with metallic elements other than the platinum group

(01.01.21)Barringerite Group phosphides

01.01.21.01 Barringerite (Fe,Ni)2P P 62m 6 m2

01.01.21.02 Schreibersite (Fe,Ni)3P I 4 4

01.01.21.03 Nickelphosphide! (Ni,Fe)3P I 4 4

01.01.21.04 Allabogdanite! (Fe,Ni)2P P nma 2/m 2/m 2/m

01.01.21.05 Melliniite! (Ni,Fe)4P P 2₁3 2 3

01.01.21.06 Monipite! MoNiP P 6 2m 6 m2

Strunz Class:

01.BD.20 01 - ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)

01.B - Metallic Carbides, Silicides, Nitrides and Phosphides

01.BD -Phosphides

01.BD.20 Melliniite! (Ni,Fe)4P P 2₁3 2 3

Other Melliniite Information

References:

NAME( AmMin, v91, p 451) PHYS. PROP.(AmMin, v91, p 451) OPTIC PROP.(AmMin, v91, p 451)

See Also:

Links to other databases for Melliniite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Ask about Melliniite here :
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Print or Cut-and-Paste your Melliniite Specimen Label here :

Melliniite

(Ni,Fe)4P
Dana No: 01.01.21.05 Strunz No: 01.BD.20
Locality:

Notes: