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Identity Helpmalachite pseudomorphs after ???

1st Nov 2007 18:27 UTCErnst A. Schnaitmann Expert

I have a specimen of malachite pseudomorphs after an unknown mineral.

What I would like to find out is what this previous mineral was.

This is from a new but the mineralogy of the locality seems to be very similar to that which is found in the DRC â€“ maybe one of you collectors, have seen something similar to this specimen from there??

The pictures labeled:

pseudo1b.jpg

pseudo1c.jpg

pseudo1d.jpg

are all depicting the same set of crystals from different viewpoints.

Please donâ€™t ask me what the crystal system is, as I am torn between cubic/isometric and tetragonal (please see my post: Tetragonal? Isometric? For more information).

The malachite ID is for sure.

My most likely choices would be: cuprite, copper, galena.

Here is also a list of minerals identified at Otjhowe:

Dioptase

Shattuckite

Quartz

Primary malachite

Chrysocolla

Barite

Wulfenite

Cuprite

Native Copper

Cerussite

Galena

Calcite

and

Shattuckite pseudomorphs after quartz â€“ I have a fantastic specimen of this type â€“ has anyone ever seen a pseudo of this type ever before (maybe in DRC material)?

Will send a photo through ASAP.

Photo information:

Malachite pseudomorphs after ??? with chrysocolla

Otjhowe, Kaokoveld, Namibia

Size: 3.5 by 2.5 cm

Ernst A. Schnaitmann

1st Nov 2007 18:28 UTCErnst A. Schnaitmann Expert

pseudo 1a

1st Nov 2007 18:30 UTCErnst A. Schnaitmann Expert

pseudo 1b

1st Nov 2007 18:31 UTCErnst A. Schnaitmann Expert

pseudo 1c

1st Nov 2007 18:32 UTCErnst A. Schnaitmann Expert

pseudo 1d

1st Nov 2007 18:48 UTCJolyon Ralph Founder

Cuprite is the most likely, I would think.

Jolyon

1st Nov 2007 20:46 UTCUwe Kolitsch Manager

Never seen such pseudomorphs, but I'd agree with Jolyon that cuprite is a good option.

11th Nov 2007 16:39 UTCClaus Hedegaard

Ernst,

Blowing the dust off the specimen greatly improves the quality of the photographs! ;-)

Some of your photos show small, cut-off corners on the cubes and the angle seems to fit with octahedral faces. This is very common in the isometric system but would be unusual in the tetragonal.

This combination does occur in Cuprite but is unusual (Goldschmidt illustrates 3-4 crystals).

Your specimen shows prominent, oriented growth of the original crystals. This does occur in Cuprite but it is unusual (I have seen it only few times).

Cube with octahedral faces is very common in native Copper and so is oriented growth of crystals.

I believe your original mineral was Copper, not Cuprite.

Claus

11th Nov 2007 17:13 UTCJasun D. McAvoy Expert

Wow!

That is a great specimen Ernst! From whom/where did you obtain this specimen, and when was it? Also, is there any way that you could take some more pics? I would love to see more if possible.

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