FMF - Friends of Minerals Forum, discussion and message board

[Carles Millan]

To Tobi, James and Don

Thanks a lot for your kind comments. I'm very glad you like the pyrite.

[Tobi]

[Carles Millan]

[Don Lum]

Great video of a remarkable specimen which belongs in one of the finest collections.

Don

[Carles Millan]

Copper

The specimen consists of a spinel twinned single crystal with a lovely natural deep black oxidation patina, with 3-dimensional complex octahedral {111} sidecar crystals growing off of its length and stacked one on top of another. The crystals show very well defined faces and edges, which is somewhat unusual with this species. I think the dark patina might be tenorite (CuO) rather than cuprite. Field collected in year 2009. Overall size: 63 mm x 10 mm. Major crystal size: 8.5 mm wide. Weight: About 13 g.

Itauz Mine, Zhilandy group, Karagandy Province, Kazakhstan.

Newer and better photos of this specimen are available at https://www.mineral-forum.com/message-board/viewtopic.php?p=83482#83482

Unless otherwise noted, photos are copyright © Carles Millan. Reproduction allowed as long as the author's name is cited and the image not modified (if it is not too much to ask...). Creative Commons Attribution Licence - Some Rights Reserved.

My Personal Site

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1119M-copper1.jpg
Mineral:	Copper
Locality:	Itauz Mine, Dzhezkazgan, Karaganda Region, Kazakhstan
Dimensions:	63 mm x 10 mm - Largest crystal size: 8.5 mm
Description:
Viewed:	40747 Time(s)

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1119M-copper3.jpg
Mineral:	Copper
Locality:	Itauz Mine, Dzhezkazgan, Karaganda Region, Kazakhstan
Dimensions:	63 mm x 10 mm - Largest crystal size: 8.5 mm
Description:
Viewed:	40406 Time(s)

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1119M-copper2.jpg
Mineral:	Copper
Locality:	Itauz Mine, Dzhezkazgan, Karaganda Region, Kazakhstan
Dimensions:	63 mm x 10 mm - Largest crystal size: 8.5 mm
Description:
Viewed:	40467 Time(s)

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1119M-copper4.jpg
Mineral:	Copper
Locality:	Itauz Mine, Dzhezkazgan, Karaganda Region, Kazakhstan
Dimensions:	63 mm x 10 mm - Largest crystal size: 8.5 mm
Description:
Viewed:	40504 Time(s)

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[Michael Shaw]

Very fine copper, Carles.

[Tobi]

Indeed a very (!) good sample of copper with remarkably well defined crystals, the colour change makes it even more attractive. Usually I don't like native copper specimens, but this one is an eyecatcher, good choice.

[Carles Millan]

[Carles Millan]

[Don Lum]

Carles, I echo what Tobi and Michael have said. A very nice native copper specimen.

Don

[Carles Millan]

[Carles Millan]

Tetrahedrite, pyrite, quartz, sphalerite

A sharp and well defined tetrahedrite tetrahedron {111} sitting on top of two lustrous and finely striated cubic {100} pyrite crystals, accompanied with a lot of colorless quartz and several sphalerite crystals here and there. Both pyrite crystals show a face along an edge that probably belongs to the pyritohedron habit {210}. Overall size: 77 mm x 71 mm x 54 mm. Tetrahedrite crystal: 24 mm on edge. Major pyrite crystal: 26 mm on edge. Weight: 273 g.

Actually a member of the series tennantite-tetrahedrite. So it might be from a Sb-rich tennantite to an As-rich tetrahedrite, somewhere between.

This specimen was involved in at least five generations. It is evident that the pyrite crystals were the first to grow. Then came the sphalerite and next the tetrahedrite, since a small crystal of the latter is placed on a crystal of the former. Finally the quartz grew over all of them. But still a fifth generation had to take place because about a dozen small pyrite cubes can be seen perched on the quartz crystals.

Mundo Nuevo mining area, Mundo Nuevo, Huamachuco, Sánchez Carrión Province, La Libertad Department, Peru.

Unless otherwise noted, photos are copyright © Carles Millan. Reproduction allowed as long as the author's name is cited and the image not modified (if it is not too much to ask...). Creative Commons Attribution Licence - Some Rights Reserved.

My Personal Site

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2276M-tetrahedrite1.jpg
Mineral:	Tetrahedrite, Pyrite, Quartz, Sphalerite
Locality:	Mundo Nuevo mining area, Mundo Nuevo, Huamachuco, Sánchez Carrión Province, La Libertad Department, Peru
Dimensions:	77 mm x 71 mm x 54 mm. Tetrahedrite crystal: 24 mm on edge. Major pyrite crystal: 26 mm on edge
Description:
Viewed:	40424 Time(s)

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2276M-tetrahedrite2.jpg
Mineral:	Tetrahedrite, Pyrite, Quartz, Sphalerite
Locality:	Mundo Nuevo mining area, Mundo Nuevo, Huamachuco, Sánchez Carrión Province, La Libertad Department, Peru
Dimensions:	77 mm x 71 mm x 54 mm. Tetrahedrite crystal: 24 mm on edge. Major pyrite crystal: 26 mm on edge
Description:
Viewed:	40182 Time(s)

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2276M-tetrahedrite3.jpg
Mineral:	Tetrahedrite, Pyrite, Quartz, Sphalerite
Locality:	Mundo Nuevo mining area, Mundo Nuevo, Huamachuco, Sánchez Carrión Province, La Libertad Department, Peru
Dimensions:	77 mm x 71 mm x 54 mm. Tetrahedrite crystal: 24 mm on edge. Major pyrite crystal: 26 mm on edge
Description:	Close-up view
Viewed:	40163 Time(s)

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[VRigatti]

Wonderful!

[Enrique Llorens]

Nice paragenesis.

[Carles Millan]

Ferberite, quartz

Tabular black ferberite crystals associated with each other like pages in a half open book, with several white quartz crystals at the bottom. Overall size: 63 mm x 54 mm x 28 mm. Major ferberite crystal: 41mm wide, 57mm tall. Mass: 233 g.

Yaogangxian Mine, Yizhang, Chenzhou Prefecture, Hunan Province, China.

Unless otherwise noted, photos are copyright © Carles Millan. Reproduction allowed as long as the author's name is cited and the image not modified (if it is not too much to ask...). Creative Commons Attribution Licence - Some Rights Reserved.