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Arnhem Cave, Windhoek Rural, Khomas Region, Namibiai
Regional Level Types
Arnhem CaveCave
Windhoek RuralConstituency
Khomas RegionRegion
NamibiaCountry

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Latitude & Longitude (WGS84):
22° 42' 5'' South , 18° 5' 47'' East
Latitude & Longitude (decimal):
-22.70160,18.09664
GeoHash:
G#: k7uygg39d
GRN:
S16E12
Type:
Cave
Köppen climate type:
BWh : Hot deserts climate
Mindat Locality ID:
5592
Long-form identifier:
mindat:1:2:5592:8
GUID (UUID V4):
0


On Arnhem farm 222, 150 km east of Windhoek. 4.5 km long cave system, the longest one in Namibia.

Mined for bat guano (in the period of 1935 to 1942 more than 10,000 tons of bat guano was extracted; https://en.wikipedia.org/wiki/Caves_of_Namibia ). Publicly accessible since 1994.

A white friable slag with arnhemite, pyrocoproite and pyrophosphite (all three names published without IMA approval) is interpreted to have resulted from the melting of ashes during the combustion of bat guano.


Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


7 valid minerals. 1 (TL) - type locality of valid minerals.

Detailed Mineral List:

ⓘ Arcanite
Formula: K2SO4
ⓘ Archerite
Formula: (K,NH4)(H2PO4)
ⓘ 'Arnhemite'
Formula: (K,Na)4Mg2(P2O7)2 · 5H2O
ⓘ Cristobalite
Formula: SiO2
ⓘ Dittmarite
Formula: (NH4)Mg(PO4) · H2O
ⓘ Mundrabillaite
Formula: (NH4)2Ca(PO3OH)2 · H2O
ⓘ 'Pyrocoproite'
Formula: (K,Na)2Mg(P2O7)
Description: Considered a pre-cursor material for arnhemite.
ⓘ 'Pyrophosphite'
Formula: K2Ca(P2O7)
ⓘ Quartz
Formula: SiO2
ⓘ Swaknoite (TL)
Formula: (NH4)2Ca(PO3OH)2 · H2O
Type Locality:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
ⓘCristobalite4.DA.15SiO2
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘArcanite7.AD.05K2SO4
Group 8 - Phosphates, Arsenates and Vanadates
ⓘArcherite8.AD.15(K,NH4)(H2PO4)
ⓘDittmarite8.CH.20(NH4)Mg(PO4) · H2O
ⓘMundrabillaite8.CJ.10(NH4)2Ca(PO3OH)2 · H2O
ⓘSwaknoite (TL)8.CJ.10(NH4)2Ca(PO3OH)2 · H2O
ⓘ'Pyrocoproite'8.FA.20(K,Na)2Mg(P2O7)
ⓘ'Pyrophosphite'8.FA.20K2Ca(P2O7)
ⓘ'Arnhemite'8.FC.20(K,Na)4Mg2(P2O7)2 · 5H2O

List of minerals for each chemical element

HHydrogen
Hⓘ Archerite(K,NH4)(H2PO4)
Hⓘ Dittmarite(NH4)Mg(PO4) · H2O
Hⓘ Mundrabillaite(NH4)2Ca(PO3OH)2 · H2O
Hⓘ Swaknoite(NH4)2Ca(PO3OH)2 · H2O
Hⓘ Arnhemite(K,Na)4Mg2(P2O7)2 · 5H2O
NNitrogen
Nⓘ Archerite(K,NH4)(H2PO4)
Nⓘ Dittmarite(NH4)Mg(PO4) · H2O
Nⓘ Mundrabillaite(NH4)2Ca(PO3OH)2 · H2O
Nⓘ Swaknoite(NH4)2Ca(PO3OH)2 · H2O
OOxygen
Oⓘ ArcaniteK2SO4
Oⓘ Archerite(K,NH4)(H2PO4)
Oⓘ CristobaliteSiO2
Oⓘ Dittmarite(NH4)Mg(PO4) · H2O
Oⓘ Mundrabillaite(NH4)2Ca(PO3OH)2 · H2O
Oⓘ QuartzSiO2
Oⓘ Swaknoite(NH4)2Ca(PO3OH)2 · H2O
Oⓘ Arnhemite(K,Na)4Mg2(P2O7)2 · 5H2O
Oⓘ Pyrocoproite(K,Na)2Mg(P2O7)
Oⓘ PyrophosphiteK2Ca(P2O7)
NaSodium
Naⓘ Arnhemite(K,Na)4Mg2(P2O7)2 · 5H2O
Naⓘ Pyrocoproite(K,Na)2Mg(P2O7)
MgMagnesium
Mgⓘ Dittmarite(NH4)Mg(PO4) · H2O
Mgⓘ Arnhemite(K,Na)4Mg2(P2O7)2 · 5H2O
Mgⓘ Pyrocoproite(K,Na)2Mg(P2O7)
SiSilicon
Siⓘ CristobaliteSiO2
Siⓘ QuartzSiO2
PPhosphorus
Pⓘ Archerite(K,NH4)(H2PO4)
Pⓘ Dittmarite(NH4)Mg(PO4) · H2O
Pⓘ Mundrabillaite(NH4)2Ca(PO3OH)2 · H2O
Pⓘ Swaknoite(NH4)2Ca(PO3OH)2 · H2O
Pⓘ Arnhemite(K,Na)4Mg2(P2O7)2 · 5H2O
Pⓘ Pyrocoproite(K,Na)2Mg(P2O7)
Pⓘ PyrophosphiteK2Ca(P2O7)
SSulfur
Sⓘ ArcaniteK2SO4
KPotassium
Kⓘ ArcaniteK2SO4
Kⓘ Archerite(K,NH4)(H2PO4)
Kⓘ Arnhemite(K,Na)4Mg2(P2O7)2 · 5H2O
Kⓘ Pyrocoproite(K,Na)2Mg(P2O7)
Kⓘ PyrophosphiteK2Ca(P2O7)
CaCalcium
Caⓘ Mundrabillaite(NH4)2Ca(PO3OH)2 · H2O
Caⓘ Swaknoite(NH4)2Ca(PO3OH)2 · H2O
Caⓘ PyrophosphiteK2Ca(P2O7)

Other Regions, Features and Areas containing this locality

AfricaContinent
African PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

en.wikipedia.org (n.d.) https://en.wikipedia.org/wiki/Caves_of_Namibia
Martini, J.E.J. (1992) Swaknoite [Ca(NH4)2·(HPO4)2·H2O, orthorhombic]: A new mineral from Arnhem cave, Namibia. Bulletin of the South African Speleological Association: 32: 72-74.
Jambor, John L., Puziewicz, Jacek (1993) New Mineral Names. American Mineralogist, 78 (9-10) 1108-1112
Martini, J.E.J. (1994) Two new minerals originated from bat guano combustion in Arnhem Cave, Namibia. South African Speleological Assoc. Bull. 33, 66-69.
Martini, J.E.J. (1997) Pyrocoproite (Mg(K,Na)2P2O7, monoclinic), a new mineral from Arnhem Cave (Namibia), derived from bat guano combustion. Proceedings 12th Internat. Congress of Speleology, La Chaux de Fonds, Switzerland, 233–235.
Jambor, J.L., Roberts, A.C. (1999) New mineral Names. American Mineralogist: 84: 193-198 (193).
Jambor, J.L., Roberts, A.C. (1999) New mineral names. American Mineralogist: 84: 193-198 (197).
von Bezing, Ludi (2007) Namibia - Minerals and Localities (1st ed.). Bode Verlag GmbH.
Marais, E., Scott, L., Gil-Romera, G., Carrión, J. (2015) The potential of palynology in fossil bat-dung from Arnhem Cave, Namibia. Transactions of the Royal Society of South Africa. 70. 1-7. (inc. map of cave)
de.wikipedia.org (n.d.) https://de.wikipedia.org/wiki/Arnhem-H%C3%B6hle
www.showcaves.com (n.d.) https://www.showcaves.com/english/other/showcaves/Arnhem.html
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