Pyrocoproite Mineral Data

General Pyrocoproite Information

Chemical Formula:

(Mg(K,Na))2P2O7

Composition:

Molecular Weight = 292.70 gm

Potassium 20.04 % K 24.14 % K₂O

Sodium 3.93 % Na 5.29 % Na₂O

Magnesium 16.61 % Mg 27.54 % MgO

Phosphorus 21.16 % P 48.50 % P₂O₅

Oxygen 38.26 % O

______ ______

100.00 % 105.47 % = TOTAL OXIDE

Empirical Formula:

Mg₂K_1.5Na_0.5(P₂O₇)

Environment:

Combustion of organic-rich quano which accumulates on the floor of caves inhabited by insect-eating bats. Considered a pre-cursor material for arnhemite.

IMA Status:

Not Approved IMA

Locality:

Arnhem Cave, Namibia. Link to MinDat.org Location Data.

Name Origin:

Named after it's derivation from bat guano combustion.

Pyrocoproite Image

Images:

Pyrocoproite

Comments: Admixture of platy indented crystals of pyrocoproite (p) and tabular opal-C (O).
Location: Ghar al Hibashi (Hebashi) is a lava cave near Harrat Nawasif/Al Buqum, located east of Makkah in the Kingdom of Saudi Arabia. Scale: See Image.
© Saudi Geological Survey

Images:

Pyrocoproite

Comments: SEM image of pyrocoproite crystals with concoidal fracture.
Location: Ghar al Hibashi (Hebashi) is a lava cave near Harrat Nawasif/Al Buqum, located east of Makkah in the Kingdom of Saudi Arabia. Scale: See Image.
© Saudi Geological Survey

Pyrocoproite Crystallography

Axial Ratios:

a:b:c =1.7348:1:2.3119

Cell Dimensions:

a = 9.41, b = 5.424, c = 12.54, Z = 4; beta = 104.35° V = 620.07 Den(Calc)= 3.14

Crystal System:

Monoclinic Space Group: Unk

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

By Intensity(I/I_o): 2.714(1), 2.882(0.94), 4.55(0.63),

Physical Properties of Pyrocoproite

Cleavage:

None

Color:

Colorless.

Density:

2.96 - 2.98, Average = 2.97

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Streak:

white

Optical Properties of Pyrocoproite

Gladstone-Dale:

CI meas= 0.065 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.115 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.178,KPDmeas= 0.1882,KC= 0.2012
Ncalc = 1.6 - 1.63

Optical Data:

Biaxial (?), a=1.558, g=1.56, bire=0.0020

Calculated Properties of Pyrocoproite

Electron Density:

Bulk Density (Electron Density)=2.92 gm/cc
note: Specific Gravity of Pyrocoproite =2.97 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Pyrocoproite= 3.43 barns/electron
U=PE_Pyrocoproite x r_electron= 10.01 barns/cc.

Radioactivity:

GRapi = 284.46 (Gamma Ray American Petroleum Institute Units)
Concentration of Pyrocoproite per GRapi unit = 0.35 (%)

Estimated Radioactivity from Pyrocoproite - barely detectable

Pyrocoproite Classification

Dana Class:

37.00.00.00 (37)Phosphate Minerals

(37.00)Without Dana Classification Numbers

(37.00.00)Phosphate, Thermocaca Series

37.00.00.00 Arnhemite* (K,Na)2Mg2(P2O7)•5(H2O) Unk Hex

37.00.00.00 Arsenowaylandite* BiAl3(AsO4)2(OH)6 R 3m 3 2/m

37.00.00.00 Auroantimonate* AuSbO3 Ortho ? Ortho

37.00.00.00 Barium-zinc-alumopharmacosiderite* (Ba,K)0.5(Zn,Cu)0.5(Al,Fe)4(AsO4)3•5(H2O) I 42m 4 2m

37.00.00.00 Chernovite-(Ce)* (Ce,Y)(AsO4) I 4₁/amd 4/m 2/m 2/m

37.00.00.00 Churchite-(Dy)* (Dy,Sm,Gd,Nd)(PO4)•2(H2O) Mono

37.00.00.00 Gengenbachite KFe3(H2PO4)2(HPO4)4•6H2OorKFe3H8(PO4)6•6H2O P 6₃mc 6mm

37.00.00.00 IMA2008-063 Pb[Zn0.25,[]0.75]Fe3H(AsO4)2(OH)6 C 2/c 2/m

37.00.00.00 IMA2009-005 (Y,Ca,REE)5[(Si,P)O4]3F P 6₃/m 6/m 2/m 2/m

37.00.00.00 IMA2009-016 Cu4H(AsO4)2(OH)3•H2O P1 1

37.00.00.00 Kerstenite? PbSeO4(?) P nma 2/m 2/m 2/m

37.00.00.00 Krasnoselskite* CoWO4 P 2/c 2/m

37.00.00.00 Laubmannite? Fe3Fe6(PO4)4(OH)12 Unk Ortho

37.00.00.00 Oxiberaunite* (Fe,Mn)Fe5(PO4)4O(OH)4•6(H2O) Mono

37.00.00.00 Parwanite (Na,K)(Mg,Ca)4Al8(PO4)8(CO3)(OH)7•30H2O P 2, Pm, P 2/m, P 2₁, Mono

37.00.00.00 Pyrocoproite* (Mg(K,Na))2P2O7 Unk Mono

37.00.00.00 Pyrophosphite* K2CaP2O7 P 2₁/n 2/m

37.00.00.00 Zinclavendulan? NaCa(Zn,Cu)5(AsO4)4Cl•4-5(H2O) Unk Ortho

Strunz Class:

08.FA.20 08 - PHOSPHATES, ARSENATES, VANADATES

08.F - Polyphosphates, Polyarsenates, [4]-Polyvanadates

08.FA -Polyphosphates, etc., without OH and H2O; dimers of corner-sharing RO4 tetrahedra.

08.FA.20 Pyrocoproite* (Mg(K,Na))2P2O7 Unk Mono

08.FA.20 Pyrophosphite* K2CaP2O7 P 2₁/n 2/m

Other Pyrocoproite Information

References:

NAME( AmMin) PHYS. PROP.(Am.Min.,Vol.84,p197,1999) OPTIC PROP.(Am.Min.,Vol.84,p197,1999)

See Also:

Links to other databases for Pyrocoproite :
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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Pyrocoproite

(Mg(K,Na))2P2O7
Dana No: 37.00.00.00 Strunz No: 08.FA.20
Locality:

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