Messum Crater - Namibia?

A couple of years ago I purchased three interesting specimens - one superb quartz crystal, and two specimens of feldspar (apparently microcline) -from the Messum Crater in Namibia. I believe the specimens/localities to be of reliable provenance - from the Manfred Forg and Peter Seroka collections.

It's taken me a while to get around to researching the locality. The Messum Crater is an unusual, complex, and remote igneous structure roughly 20km in diameter, and located roughly half-way between the Brandberg and the Namibian coast (Latitude -21.383; Longitude 14.216). The locality gets a short write-up in Von Bezing's "Namibia" book but, to my surprise, we don't appear to have an entry for the locality in Mindat.

Rather than jump in with both feet and try and enter a new locality I thought I'd post here first in case there is an alternative name - but this is undoubtedly a locality worthy of an entry.

I will post a photo of the quartz in due course, because it's a fascinating and unusual crystal, but I'd also be very interested to hear from anyone who has information about this locality.

mal

Here is the Messum Crater quartz crystal. It's a doubly terminated crystal which grew more or less symmetrically from the point of matrix attachment mid-crystal. Length is 10cm. My photography does it far less than justice in that the crystal has a number of rehealed growth fractures which are not really discernible here.

mal

Do you have reason to believe that the quartz and feldspar crystals were actually found in the museum crater? It is much more likely that they were found at a quartz locality in Namibia and not at the crater? Does the quartz have any zones of pale amethyst in it? I thought I might have seen a touch of light colored amethyst in the crystal, but could not be sure. The bit of matrix with the quartz crystal, what is that? A druse of small quartz crystals?

Rock Currier
Crystals not pistols.

Hi Rock,

The quartz crystal came from the Manfred Forg collection. He was a missionary in northern Namibia and assembled a formidable collection during the 1970s and 1980s with the assistance of Dr Hans-Josef Lauenstein who was at the time a mineralogist working for the Tsumeb Corporation. This was why I said that I thought the provenance of the quartz to be reliable. To answer your questions (a) there is no hint of amethyst - the red colouration is an artefact I'm afraid, and another symptom of my poor photography! (b) the matrix does indeed consist of finely crystallised drusy quartz.

The feldspars were from the Peter Seroka collection. Peter is a German collector who sold his collection a few years ago to a dealer in the UK. I was told that he had visited the Messum Crater personally and that this material was self-collected. Beyond that I can't say for sure, but I have no reason to doubt the account from the dealer on this one. Certainly the specimens are consistent with the simple assemblage listed by von Bezing.

Cheers
mal

I have seen many quartzes from Messum crater area ... the most outstanding were hedgehogs of pale amethyst reverse scepters ("antenna quartzes"). Although Von Bezing gives only a shorter note i met some collectors in Uis, Windhoek and Swakopmund who had material from there - and after i asked they confirmed that it was not from Gobobos Mts. as i suspected first.

cheers
Roger

Hi Malcolm

yes, I have personally collected quartzes and feldspars in the Messum crater. Both minerals occurr in abundance, however, due to the remoteness of the crater, missing paved streets and due to missing information related to minerals this locality is still not so well known. A 4-wheel car, a large supply of water and tents are needed for a successful collecting expedition.

Quartzes occur as single crystals up to 30 cm, either transparent-clear, mainly single xtls. However, most interesting are outstanding and perfectly formed amesthyst scepters with colorless stems and violet heads, some up to 10-15 cm length on or off matrix.

The feldspars are microclines; perfect sharp textbook-crystals from 5-25 cm; they occur mainy in eroded rock debris or in sand. There are so many at some places, that one can afford the luxury to select only the best ones. During my last visit to the crater I had collected too many crystals, it must have been thousands, that I had to leave the largest part near my camp ground.

Best collecting time is betwen 07 and about 10 a.m. Reason is, that the crater is full of very dangerous snakes (side winders and rattlers). Due to the cold of the nights, which is based on the strong fog from the nearby Atlantic ocean, overflowing the Western crater walls, the snakes are still stiff and appear lifeless in the early morning; however, once the sun breaks through the fog, those animals wake up and start hunting. As most of the beautiful amethst sceptes occur in rock cavities, it is thus not advisable, to touch or knock at rocks after 10:00 a.m.

Regards
Peter Seroka

Hi Peter,

rattlers in Africa? :D
(sorry, I couldn't resist)

Anyway, are the feldspar crystals from volcanic or from plutonic rocks or dikes?
I thought it is a "real "volcanic crater (haven't been there, though).

Amir

Thanks Peter, Roger,

Peter - I hope you didn't mind me taking your name in vain, but I am the owner of a couple of Messum Crater feldspar specimens that were, I believe, collected by you.

I was based in South Africa for eight years and collected extensively in Namibia during the 1980s, but never visited the Messum Crater. It sounds like one for the future - with all the appropriate precautions of course. (Not sure who imported the "rattlers" though!)

Bottom line is that we do need to add a locality entry for Messum Crater here on mindat, and I'll try and master the technology to do just that in the next few days - unless anyone beats me to it.

Cheers
mal

Thanks all. Added: [www.mindat.org].

Thanks Uwe - not least for sparing my blushes with the technology!!!

mal

Is the crater a real impact feature? There I might expect impact shocked quartz, but not real well formed quartz crystals.

Rock Currier
Crystals not pistols.

The Messum Crater is an intrusion, as is Brandberg, Erongo, Spizkopje etc.
Gobobosebberge is the norternmost part of the Messum Crater complex of intrusive rocks.
The Geological map of this part of Namibia is one of the most explicit of any I have ever seen. I highly recommend it.
Geological Survey of namibia, Sheet 2114 - Omaruru, scale 1:250 000

Rock,

The satellite photo is very informative too, in terms of the structure. In fact further to Peter Lyckberg's comment on the geological map, I have also spent many hours with Google Earth over this part of Namibia. The features are quite extraordinary and pleasingly uninterrupted by cities, roads and railways etc. I can also send you privately (or anyone else who's interested come to that) a couple of PDFs on the geology if you're interested.

mal

Yes, google earth is excellent!
Have also a look at Erongo and the ring dike around it (N, NW direction easiest visible)

Hi Amir

it goes without saying: You' re right !
There ain't no rattlers - neither in Namibia nor in Africa.
The larger snakes are adders, e.g. puff-adders.

Thanks
Peter

Nope, no rattlers...but good lord, has anyone else been chased by a pofadder? That was one of the scariest moments of my life...