Aris Quarries, Aris, Windhoek Rural, Khomas Region, Namibiai

Regional Level Types
Aris Quarries	Group ofQuarries
Aris	Village
Windhoek Rural	Constituency
Khomas Region	Region
Namibia	Country

Two phonolite quarries, the Railway Quarry and the Ariskop Quarry, are located 25 km S of Windhoek, on the road to Rehoboth. The two open pits are less than 1 km apart. The Railway Quarry (west side of the road) has been inactive [in 2011] for the last 10–15 years, whereas the Ariskop Quarry (east side of the road) has been active during at least the last decade and was active in 2011. Most of the minerals, including the type minerals, collected in recent years came from the workings of the Ariskop Quarry.
Note that each of the two quarries extracts material from a different intrusion, differentiated by its geochemical features (F. Koller, pers. comm. to U. Kolitsch, 2015).

Mineralogy is somewhat similar to that of the Saint-Amable sill (Demix-Varennes quarry), Québec, Canada, the Point of Rocks phonolite in New Mexico, USA and, in part, to that of Mont Saint-Hilaire. The most notable difference between these localities is the extreme scarcity of eudialyte-group minerals at Aris.

IMPORTANT NOTES on the mineral list (updated/cleaned up in May, June, and July 2006, September & December 2007, August 2008, August 2009, May 2011, October 2011 and April 2016 by Uwe Kolitsch; see also booklet of Kolitsch et al., 2016):

1) Several other species were reportedly 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 some 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) and von Knorring et al. (1992) has been confirmed – as a eudialyte-group mineral – for the first time only in 2008 (a single specimen) and then again in 2009 (another single specimen) and 2016 (several specimens). EDS analyses of several specimens suggest eudialyte sensu stricto (Kolitsch et al., 2016); no EPMA of these eudialyte-group specimens are available yet. 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, Moscow).

Other Databases

Wikipedia:	https://de.wikipedia.org/wiki/Aris_Quarries
Wikidata ID:	Q23790598

Other Regions, Features and Areas containing this locality

References