Pyrophosphite Mineral Data

General Pyrophosphite Information

Chemical Formula:

K2CaP2O7

Composition:

Molecular Weight = 287.36 gm

Potassium 24.35 % K 29.34 % K₂O

Sodium 0.80 % Na 1.08 % Na₂O

Calcium 13.81 % Ca 19.32 % CaO

Magnesium 0.51 % Mg 0.84 % MgO

Phosphorus 21.56 % P 49.40 % P₂O₅

Oxygen 38.97 % O

______ ______

100.00 % 99.97 % = TOTAL OXIDE

Empirical Formula:

K_1.79Na_0.1Ca_0.99Mg_0.06P₂O₇

Environment:

Arnhemite and pyrophosphite are the principal phases in a slag that forms a thin layer in a profile of cave soil. The slag is interpreted to have resulted from the melting of ashes during the combustion of bat quano.

IMA Status:

Not Approved IMA

Locality:

Arhem Cave, 150 km east of Windhoek, Namibia. Link to MinDat.org Location Data.

Name Origin:

Named after the Greek pyros, meaning fire and the element name - Phosphorus.

Search for Pyrophosphite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Pyrophosphite Crystallography

Axial Ratios:

a:b:c =1.7233:1:2.2917

Cell Dimensions:

a = 9.742, b = 5.653, c = 12.955, Z = 4; beta = 104.35° V = 691.19 Den(Calc)= 2.76

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/n

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

By Intensity(I/I_o): 2.821(1), 2.987(0.64), 3.137(0.33),

Physical Properties of Pyrophosphite

Cleavage:

None

Color:

White.

Density:

2.75 - 2.76, Average = 2.75

Diaphaneity:

Transparent

Fracture:

Friable - The crumbly disintegration of earthy materials or highly fractured minerals.

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Pyrophosphite

Gladstone-Dale:

CI meas= -0.031 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.029 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1978,KPDmeas= 0.1982,KC= 0.1922
Ncalc = 1.53

Optical Data:

Biaxial (?), a=1.543, g=1.549, bire=0.0060

Calculated Properties of Pyrophosphite

Electron Density:

Bulk Density (Electron Density)=2.72 gm/cc
note: Specific Gravity of Pyrophosphite =2.76 gm/cc.

Fermion Index:

Fermion Index = 0.0009101723
Boson Index = 0.9990898277

Photoelectric:

PE_{Pyrophosphite}= 5.20 barns/electron
U=PE_{Pyrophosphite} x r_electron= 14.15 barns/cc.

Radioactivity:

GRapi = 346.36 (Gamma Ray American Petroleum Institute Units)
Concentration of Pyrophosphite per GRapi unit = 0.29 (%)

Estimated Radioactivity from Pyrophosphite - barely detectable

Pyrophosphite 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 Pyrophosphite Information

References:

NAME( AmMin, v84:193) PHYS. PROP.(Am.Min.,Vol.84,p193,1999) OPTIC PROP.(Am.Min.,Vol.84,p193,1999)

See Also:

Links to other databases for Pyrophosphite :
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

Search for Pyrophosphite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Pyrophosphite :

A Bijoux Google Search for Pyrophosphite
Adam's Minerals Google Search for Pyrophosphite
Cape Minerals Google Search for Pyrophosphite
Dakota Matrix Minerals Google Search for Pyrophosphite
Excalibur Mineral Corp. Google Search for Pyrophosphite
Exceptional Minerals Google Search for Pyrophosphite
John Betts Fine Minerals Search for Pyrophosphite
McDougall Minerals Google Search for Pyrophosphite
Mineral News Website Link
Rock and Mineral Shows Google Search for Pyrophosphite
Weinrich Minerals, Inc. Google Search for Pyrophosphite

Ask about Pyrophosphite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Pyrophosphite

K2CaP2O7
Dana No: 37.00.00.00 Strunz No: 08.FA.20
Locality:

Notes: