FMF - Friends of Minerals Forum, discussion and message board

[Herman van Dennebroek]

Hallo to all the members of FMF.
I'm collecting minerals for more than 50 years. I'm collecting "worldwide" but there are some mines or regions which have my special interest. I have small separated regional collections from Tuscany, Italy; from Elba, Italy; from Binntal, Switzerland and Idar-Oberstein, Germany. In these small collections are much self-collected specimen. One of the mines that I real like is the Tsumeb mine. From this locality I have a collection from which I like to share with you some parts. I hope you enjoy it.

[Antonio Alcaide]

Herman, your selected collection is more than welcome! Nice taste.

And Tsumeb is a legendary locality for collectors all over the world!

Regards

[gemlover]

Thank you for the fantastic pictures. Lovely specimens.

John

[GneissWare]

Very nice!

[Montanpark]

Herman,
thanks for sharing, very nice specimens .. and i am a fan of Tsumeb minerals too!

Cheers
Roger

[Herman van Dennebroek]

Hallo Antonio, John, Roger and GneisWare,

Thanks a lot for your positive reactions.

Looking at my pictures on FMF I must say that the original pictures (large resolution, large file) much sharper are than the pictures on the Internet. I hope it still gives a good impression about the specimen.

I promised to continue with posting, well here they are. The pictures are just an excerpt of my Tsumeb collection which contains about 210 specimens.

I hope that you and more of the FMF members will enjoy the pictures
.
Regards,
Herman

[Jordi Fabre]

[bugrock]

Herman,

Excellent selection of specimens!

Portions of your dolomite pseudomorph look botryoidal but other portions look like euhedral crystals with rounded edges. Are there any crystal casts at the bottom of the specimen? I wonder if dolomite might be at times botryoidal in habit?

We have in Michigan one occurrence of baryte with a botryoidal habit that reminded me a bit of your piece, but the baryte apparently grew on anhydrite casts. See Mindat link:

https://www.mindat.org/forum.php?read,11,204970,204970#msg-204970

George

[Herman van Dennebroek]

Thanks Jordi for your reaction.

I had the same idea as you, but the pictures in Gebhard's book "Tsumeb" (the English version) brings me doubt. The shape of the Stolzites on page 235 and 237 are very similar to Wulfenite, especially the picture at the bottom on page 237.

In my catalogue I have written Wulfenite (perhaps Stolzite).

[Herman van Dennebroek]

Hallo George,

Thank you for your compliment.

The dolomite pseudo is is not botryoidal. Actually it is a perimorphose; there are some casts at the bottom of the specimen. It is build from very small rhomboeder crystals. Some of the crystals have the typical saddle shape.

I can understand that on first sight my dolomite remembers you on your baryte.
The baryte is interesting stuff.

Herman

[Jim Robison]

Herman

I collect Tsumeb dolomite casts (epimorphs/perimorphs). Your specimen is very interesting, because it has the possibility of being a cast after azurite, or perhaps cerussite. Could you show us a picture of the bottom of the piece please. It would be helpful to know if there are any associated minerals. The tall tabular mold on the right side of the picture would be interesting to see from several viewpoints, including one from the top looking down the long axis of the cast. You might also want to look at several of the other tabular mold segments, to see if there is any hint of the precursor crystal shape. In any event, a very nice rock. Wish it was in my collection, but happy to see you appreciate what it is.

Jim Robison

[Herman van Dennebroek]

Hallo Jim,
Thanks for your reaction. You mention a interesting question.

There are hardly no associated minerals on the specimen.
I will make more photos of the specimen, but not now. Wednesday I am going to Tucson and I had to do a lot of things before leaving. Making good pictures takes to much time now.

Later in February when I'll be back I'll make the pictures you wanted.

Regards,
Herman

[Jim Robison]

Herman

I'll look forward to some pictures in late February. The Tucson madness begins, and I will be down there as well, in a variety of venues. I'm exhibiting at the Main TGMS show (Colorful Carbonates) of which about half the pieces will be Tsumeb. It will be in the general exhibits area, which is generally at one end of the exhibit hall. Maybe we will cross paths sometime during the time you are there. I will be principally wandering around at the Hotel Tucson City Center (old Inn Suites) and some time at the Westward Look show as well.

Jim

[Herman van Dennebroek]

Hallo Jim,

Probably we meet each other in Tucson. It would be nice to talk about Tsumeb dolomites/calcites.

I've looked at your "cast" pictures. Wonderful specimen!!

I hope I am able to spend some time at the exposition; we fly back on saturday 17the.

Regards,
Herman