Aris Quarries (Ariskop Quarry; Railway Quarry), Aris, Windhoek, Windhoek District, Khomas Region, Namibia

Phonolite quarries (Railway quarry and Ariskop quarry), 25 km S of Windhoek, on the road to Rehoboth. Paragenesis is similar to that of the Demix-Varennes quarry, Québec, Canada, and, in part, to that of Mt Saint-Hilaire. The quarries are worked intermittently.


IMPORTANT NOTES on the mineral list (updated/cleaned up in May, June and July 2006, September & December 2007, August 2008, August 2009 by Uwe Kolitsch):

1) Several other species were reportly found and/or sold by dealers, but have never been confirmed. They are, in alphabetical order:
- canasite
- gyrolite (confused with globular fluorite? there is also an apparently new mineral with an appearance similar to that of gyrolite)
- hiorthdalite II (confused with nenadkevichite or other labuntsovite-group mineral?)
- hisingerite
- iraqite-(La) (confused with sazhinite, probably because the powder diffraction patterns are similar)
- isokite (a sample labeled as "isokite" contained no isokite at all)
- sepiolite-Fe
- tetranatrolite (a sample labeled as "tetranatrolite" turned out to be makatite)
- zakharovite (in fact, the mineral is the unnamed Fe-analogue of zakharovite)

2) Eudialyte, originally mentioned in von Knorring & Franke (1987) has been confirmed for the first time only in 2008 (a single specimen) and then again in 2009 (another single specimen). Most "eudialytes" in collections are probably villiaumite.


A larger number of presently unidentified minerals, some of them certainly new to science, are under study in various laboratories, partly in collaborative efforts (Vienna, Tempe, Copenhagen, Oslo, Ottawa).

References:
- von Knorring, O. and Franke, W. (1987): A preliminary note on the mineralogy and geochemistry of the Aris phonolite, SWA/Namibia. Comm. Geol. Surv. S.W.Africa (Namibia) 3, 61.
- von Knorring O., Petersen O. V., Karup-Moller S., Leonardsen E. S., Condliffe E. (1992): Tuperssuatsiaite from Aris phonolite. N. J. Mineral., 1992: 145-152.
- Niku-Paavola V. (1997): Alkaline rocks in the Aris area, Central Namibia. Ph. D. Thesis Department of Geology and Mineralogy, University of Helsinky, 71 pp.
- Petersen O. V., Fockenberg P. C., Toft P. C., Rattay M. (1997): Natrophosphate from Aris phonolite. N. J. Mineral., 1997: 511-517.
- Garvie L. A. J., Devouard B., Groy T. L., Càmara F., Buseck P. R. (1999): Crystal structure of kanemite, NaHSi2O5·3H2O, from the Aris phonolite, Namibia. Amer. Mineral., 87: 1170-1175.
- Niedermayr G., Gault R. A., Petersen O. V., Brandstatter F. (2002): Korobitsynite from Aris phonolites, Windhoek, Namibia. N. J. Mineral., 2002: 42-48.
- Sturla M., Yakovenchuk V. N., Bonacina E. (2005): Aris, Namibia: geo-paragenesi e minerali. Micro (località), vol. 2005, n. 1, 55-80.
- Piilonen, P. C., Rowe, R., Grice, J. D., Gault, R. A., Cooper, M., Kolitsch, U. and Lechner, B. (2005): Two new sodium rare-earth fluorcarbonates from the Aris phonolite, Namibia. Oral presentation, 32nd Rochester Mineralogical Symposium, Rochester, NY, USA, April 14-17, 2005; abstract in Program and Abstracts, 27-28.
- Ellingsen, H. V. (2006): Sérandit aus Aris, Namibia. Mineralien-Welt 17 (3), 51. (in German)
- Uwe Kolitsch, 2000-2009, unpublished results.

http://www.koeln.netsurf.de/~w.steffens/aris.htm