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Tsumeb pseudomorphoses
  
  Index -> What is it? - Where is it from?
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Herman van Dennebroek




Joined: 07 Feb 2011
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PostPosted: Apr 11, 2021 06:02    Post subject: Tsumeb pseudomorphoses  

Dear Tsumeb enthusiasts,
In preparing a lecture on pseudomorphoses I also include some Tsumeb specimens.
The photos I send now shows a piece that I have in my collection for over 30 years. It can be seen that the Zn-olivinite (earlier called cupro adamine) has been partially or completely converted into a brown-red crystal. The question is what is the substitute mineral. At first I thought of hematite or an iron hydroxide. But the streak color is a bit lighter (less brown) than that of hematite. The structure of the brown-red material is finely grained. I found the same fine-grained material on a small specimen with mainly carminite. The carminite has filled cavities in the form of a fine-ray layers.
Given the chemical composition of carminite, this mineral is in my opinion more suitable to replace the Zn olivinite than hematite.
I like to read your opinions,
Greetings Herman



Pict 1.jpg
 Mineral: Zincolivenite
 Locality:
Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia
 Dimensions: Fov 10 cm
 Description:
 Viewed:  976 Time(s)

Pict 1.jpg



Pict 2.jpg
 Mineral: Zincolivenite
 Locality:
Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia
 Dimensions: Fov 2,1 cm
 Description:
 Viewed:  973 Time(s)

Pict 2.jpg



Pict 3.jpg
 Mineral: ??? after Zincolivenite
 Locality:
Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia
 Dimensions: 2,1 cm
 Description:
 Viewed:  977 Time(s)

Pict 3.jpg



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