Arsenopyrite Mineral Data

General Arsenopyrite Information

Chemical Formula:

FeAsS

Composition:

Molecular Weight = 162.83 gm

Iron 34.30 % Fe

Arsenic 46.01 % As

Sulfur 19.69 % S

______

100.00 %

Empirical Formula:

Fe³⁺AsS

Environment:

High temperature veins. Found in igneous pegmatites and contact metamorphic rocks.

IMA Status:

Valid Species (Pre-IMA) 1847

Locality:

Most common arsenic-bearing mineral found world wide. Link to MinDat.org Location Data.

Name Origin:

Named after the minerals chemical composition.

Name Pronunciation:

Arsenopyrite + Pronunciation

Synonym:

Arsenical pyrite

Bismuthian Arsenopyrite

Cobaltian Arsenopyrite

ICSD 62400

Mispickel

PDF 42-1320

Arsenopyrite Image

Images:

Arsenopyrite Siderite

Comments: White, metallic arsenopyrite and tan siderite crystals.
Location: Panasqueira (2000, 3rd level), in the region of Beira Baixa, Portugal. Scale: 11 x 7 cm.
© Fabre Minerals

Images:

Arsenopyrite

Comments: Polished section (PPL) showing crystalline aggregate of arsenopyrite (asp) in massive sphalerite (sp), typical of the main sphalerite lens.
Location: Giant Kidd Creek Volcanogenic Massive Sulfide deposit, Western Abitibi Subprovince, Timmins, Ontario, Canada. Scale: F.V. = 0.25 mm.
© National Resouces of Canada

Arsenopyrite Crystallography

Axial Ratios:

a:b:c =1.0105:1:1.0193

Cell Dimensions:

a = 5.74, b = 5.68, c = 5.79, Z = 4; beta = 112.17° V = 174.82 Den(Calc)= 6.19

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 2.662(1), 2.677(1), 2.418(0.95),

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Forms: ( 0 1 2) ( 1 1 0)

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Physical Properties of Arsenopyrite

Cleavage:

{110} Distinct

Color:

Tin white, Light steel gray.

Density:

6.07

Diaphaneity:

Opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

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

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

5 - Apatite

Luminescence:

Non-fluorescent.

Luster:

Metallic

Magnetism:

Magnetic after heating

Streak:

black

Optical Properties of Arsenopyrite

RL Anisotrophism:

Strong, red-violet.

RL Color:

White, faint yellow tint.

RL Pleochroism:

Weak, white with bluish tint to faint reddish yell.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Arsenopyrite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	49.90	53.00
420 nm	49.20	53.00
440 nm	48.50	53.00
460 nm	48.30	53.00
480 nm	48.50	52.80
500 nm	48.90	52.70
520 nm	49.40	52.40
540 nm	49.70	52.00
560 nm	50.20	51.60
580 nm	50.50	51.30
600 nm	50.80	51.10
620 nm	51.00	50.80
640 nm	51.10	50.70
660 nm	51.10	50.60
680 nm	51.10	50.50
700 nm	51.00	50.50

**Calculated Relative Intensity Colors of Arsenopyrite in Air**
Relative Intensity	0%	20%	40%	60%	80%	100%	120%	140%	160%	180%
R₁
R₂

Calculated Properties of Arsenopyrite

Electron Density:

Bulk Density (Electron Density)=5.70 gm/cc
note: Specific Gravity of Arsenopyrite =6.19 gm/cc.

Fermion Index:

Fermion Index = 0.0087478423
Boson Index = 0.9912521577

Photoelectric:

PE_Arsenopyrite= 44.13 barns/electron
U=PE_Arsenopyrite x rElectron Density= 251.61 barns/cc.

Radioactivity:

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

Arsenopyrite Classification

Dana Class:

02.12.04.01 (02)Sulfides - Including Selenides and Tellurides

(02.12)where Am Bn Xp, with (m+n):p=1:2

(02.12.04)Arsenopyrite Group (Monoclinic: P21/c (Pseudo-orthorhombic))

02.12.04.01 Arsenopyrite FeAsS P 2₁/c 2/m

02.12.04.02 Gudmundite FeSbS P 2₁/n 2/m

02.12.04.03 Osarsite (Os,Ru)AsS P 2₁/c 2/m

02.12.04.04 Ruarsite RuAsS P 2₁/c 2/m

02.12.04.05 Iridarsenite (Ir,Ru)As2 P 2₁/c 2/m

02.12.04.06 Clinosafflorite (Co,Fe,Ni)As2 P 2₁/n 2/m

Strunz Class:

02.EB.20 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.E - Metal Sulfides, M:S ï¿½ 1:2

02.EB -M:S = 1:2, with Fe, Co, Ni, PGE, etc.

02.EB.20 Arsenopyrite FeAsS P 2₁/c 2/m

02.EB.20 Gudmundite FeSbS P 2₁/n 2/m

02.EB.20 Ruarsite RuAsS P 2₁/c 2/m

02.EB.20 Paxite CuAs2 P 2₁/c 2/m

02.EB.20 Osarsite (Os,Ru)AsS P 2₁/c 2/m

Other Arsenopyrite Information

References:

NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)

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Arsenopyrite

FeAsS
Dana No: 02.12.04.01 Strunz No: 02.EB.20
Locality:

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