VOOZH about

URL: https://www.mindat.org/min-7261.html

⇱ Pyrophosphite: Mineral information, data and localities.

👁 Image
Now Featuring: The Bruce Carter Collection at Heritage Auctions, Live May 16th
Log InRegister
AboutSupport UsPhotosDiscussionsSearchLearnMore

Pyrophosphite

This page is currently not sponsored. Click here to sponsor this page.
Formula:
K2Ca(P2O7)
Lustre:
Vitreous
Crystal System:
Monoclinic
Name:
Named after the Greek pyros, meaning fire and the element name - Phosphorus.
A pyrophospate originated from bat guano combustion in Arnhem Cave, Namibia, about 2000 years ago. Cause of combustion unknown.

Originally described (together with another pyrophosphate, 'pyrocoproite') from Arnhem Cave, Windhoek District, Khomas Region, Namibia.
See also arnhemite.

Compare grahampearsonite, canaphite, wooldridgeite; 'arnhemite', and UM1991-10-PO:BaCaHMgSr.


Unique IdentifiersHide

This section is currently hidden. Click the show button to view.
Mindat ID:
7261
Long-form identifier:
mindat:1:1:7261:4

IMA Classification of PyrophosphiteHide

This section is currently hidden. Click the show button to view.
IMA status notes:
Intermediate member of a solid-solution series

Classification of PyrophosphiteHide

This section is currently hidden. Click the show button to view.
8.FA.20

8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
A : Polyphosphates, etc., without OH and H2O; dimers of corner-sharing RO4 tetrahedra.
38.5.8.

38 : ANHYDROUS NORMAL PHOSPHATES, ARSENATES, AND VANADATES
5 : Miscellaneous

Physical Properties of PyrophosphiteHide

This section is currently hidden. Click the show button to view.
Vitreous

Optical Data of PyrophosphiteHide

This section is currently hidden. Click the show button to view.
Type:
Biaxial
RI values:
nα = 1.543 nγ = 1.549
Max. Birefringence:
δ = 0.006
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.

Surface Relief:
Moderate
Dispersion:
weak

Chemistry of PyrophosphiteHide

This section is currently hidden. Click the show button to view.
Mindat Formula:
K2Ca(P2O7)
Element Weights:
Element% weight
O38.326 %
K26.760 %
P21.199 %
Ca13.715 %

Calculated from ideal end-member formula.

Crystallography of PyrophosphiteHide

This section is currently hidden. Click the show button to view.
Crystal System:
Monoclinic

Other Language Names for PyrophosphiteHide

This section is currently hidden. Click the show button to view.

Related Minerals - Strunz-mindat GroupingHide

This section is currently hidden. Click the show button to view.
8.FA.Phosphocyclite-(Fe)Fe2+2(P4O12)Mon. 2/m : B2/b
8.FA.Phosphocyclite-(Ni)Ni2(P4O12)Mon. 2/m : B2/b
8.FA.GrahampearsoniteCa2P2O7Tet. 4 : P41
8.FA.BakakiniteCa2V2O7Tric. 1 : P1
8.FA.LisaniteCaNiP2O7Tric. 1 : P1
8.FA.ShasuiteCaNi3(P2O7)2Mon. 2/m : P21/b
8.FA.NabateaiteFe2P2O7Tric. 1 : P1
8.FA.SamraiteNi2P2O7Mon. 2/m : P21/b
8.FA.AnastasenkoiteCaFe2+(P2O7)Tric. 1 : P1
8.FA.05Blossiteα-Cu2(V2O7)Orth. mm2 : Fdd2
8.FA.10Ziesiteβ-Cu2(V2O7)Mon. 2/m : B2/b
8.FA.15'UM1999-17:O:PbV'Pb4V2O9 or Pb4(VO4)2O
8.FA.15ChervetitePb2(V2O7)Mon. 2/m : P21/b
8.FA.20YamhamelachiteKCrP2O7Mon. 2/m : P21/b
8.FA.20'Pyrocoproite'(K,Na)2Mg(P2O7)Mon.
8.FA.25Petewilliamsite(Ni,Co)30(As2O7)15Mon. 2 : B2

RadioactivityHide

This section is currently hidden. Click the show button to view.

Other InformationHide

This section is currently hidden. Click the show button to view.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for PyrophosphiteHide

This section is currently hidden. Click the show button to view.
mindat.org URL:
https://www.mindat.org/min-7261.html
Please feel free to link to this page.

References for PyrophosphiteHide

This section is currently hidden. Click the show button to view.

Localities for PyrophosphiteHide

This section is currently hidden. Click the show button to view.

Showing 2 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the 👁 Image
symbol to view information about a locality. The 👁 Image
symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

This section is currently hidden. Click the show button to view.
👁 Image
- This locality has map coordinates listed. 👁 Image
- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. 👁 Image
- Good crystals or important locality for species. 👁 Image
- World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Namibia
  • Khomas Region
    • Windhoek Rural
Martini (1994) +1 other reference
Saudi Arabia
  • Mecca Region
Saudi Geological Survey Open-File ... +1 other reference
Quick NavTopUnique IdentifiersIMA Classification Classification Physical Properties Optical Data Chemistry Crystallography Other LanguagesStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 4, 2026 13:06:32 Page updated: March 14, 2026 17:59:11
Go to top of page