Zinccopperite and Tongxinite

While checking the occurrences of Zinccopperite and Tongxinite listed in the database, and adding references, I came across some major inconsistencies in the use of the name Zinccopperite.

A Cu-Zn alloy with composition Cu7Zn4 was first described by Xiao et al. (1998) from Xinfanping Cu deposit in Sichuan Province. The title of the paper seems to introduce the name "Zinccopperite" as a varietal name; according to Jambor and Roberts (1999), the text refers to zinccopperite as "tentatively named". However, they come to the conclusion that "species rather than varietal status is intended", which is indicated "by references to danbaite (CuZn2) and zhanghengite (CuZn) as other varieties in the Zn-Cu alloy series." With reference to this article, Zinccopperite made its way into the database as a mineral published without approval.
Though, in later papers by Chinese authors, both on the Xinfanping occurrence and on occurrences of other Cu-Zn alloys (see also the references listed on the Tongxinite page), the name Zinccopperite is used as a generic name for Cu-Zn alloys, including the Cu7Zn4 phase from Xifanping and also tongxinite, danbaite, brass, and zhanghengite. In fact, the majority of Chinese papers on zinccopperite do not refer to Cu7Zn4, but to alloys with different composition, mostly Cu2Zn (Tongxinite). An overview of the occurrences reported so far is given in a paper by Xie Yuling et al. (2006), along with the compositions of the respective minerals, and it becomes clear that most "zinccopperites" are in fact Tongxinite, and that Xifanping is still the only known occurrence of a phase with composition Cu7Zn4 (funnily, the also use the name "Jupiter" for native tin). They also give an overview of the nomenclature used so far by Chinese authors, and explain that they regard "Zinccopperite" in fact as a generic name for Cu-Zn alloys. This is also outlined in a paper by Sun et al. (2002).

Interestingly, none of the papers I have checked so far is using the name "Tongxinite" when they are dealing with Cu2Zn. However, since "Tong" and "Xin" mean "Copper" and "Zinc", respectively, I suspect that there is no difference between "Zinccopperite" and "Tongxinite" in the Chinese language, and that the name "Zinccopperite" may have been introduced as an attempt of an English translation. This leads to the question whether "Tongxinite" is also just a descriptive term for Cu-Zn alloys, or whether it was really intended as a name for the specific phase Cu2Zn (someone familiar with the Chinese language will have to check the original papers, not just the abstracts to solve this !).

The logical conclusion to this mess would be to "re-define" Zinccopperite as a generic name, and list the Xifanping material as unnamed, and possibly, to do the same with Tongxinite and Cu2Zn. They both aren't official names, anyway.


What do others think ?
Please give me your comments.


References:
===========

(1) Yanfu Xiao, Yan Sun, Yan Lu, Chunqi Wen, and Jiangzhen Wang (1998): Zinccopperite - a new variety of zinc-copper intermetallic compounds discovered in a porphyry-copper deposit. Acta Geologica Sinica 72(3), 308-313.
(2) Jambor, J.L., and Roberts, A.C. (1999): New Mineral Names. American Mineralogist 84, 990-994 [http://www.minsocam.org/msa/AmMin/toc/Abstracts/1999_Abstracts/MJ99_Abstracts/Jambor_p990_99.pdf]
(3) Sun, Y., Xiao, Y., Wen, C., et al. (2002): The discovery of genesis of zinccopperite in a porphyry copper deposit in Xifanping, Sichuan Province. Bulletin of Mineralogy, Petrology and Geochemistry 21(4), 266-267 (in Chinese with English abstract).
(4) Sun, Y., Xiao, Y., and Wang, J. (2003): The discovery features of the native zinc-copper intermetallic compound in China. Journal of Mineralogy and Petrology 23(2), 11-14 (in Chinese with English abstract).
(5) Xie Yuling, Hou Zengqian, Xu Jiuhua, Yuan Zhongxin, Bai Ge, and Li Xiaoyu (2006): Discovery of Cu-Zn, Cu-Sn intermetallic minerals and its significance for genesis of the Mianning-Dechang REE Metallogenic Belt, Sichuan Province, China. Science in China, Series D (Earth Sciences), 49(6), 597-603.



Edited 1 time(s). Last edit at 05/03/2008 01:41PM by Peter Haas.

Jeffrey would probably have the best information about this.

Chinese authors have published the 'tentative' names zinccopperite and tongxinite in two different papers; both phases and their names have not been submitted to the CNMNC for approval.
Zinccopperite: Xiao et al. in Acta Geologica Sinica 72(3) (1998), 308-313, abstract in Am. Mineral., 84 (1999), 992. Type locality: Xifanping area, Sichuan Province.
Tongxinite: Shuai et al. in Acta Mineralogica Sinica 18 (1998), 509-513, abstract in Am. Mineral., 85 (2000), 264. Type locality: Yulong and Malasondo districts, Tibet.

Two names, two localities, thus two phases?

Of course, Cu2Zn (tongxinite) and Cu7Zn4 (zinccopperite) are quite close to each other in composition. In their more recent papers, the Chinese perhaps have realised themselves that two different teams described the same material with two 'tentative' names. It shows that they should contact more frequently the CNMNC ... Moreover, the Chinese also have their own national commission on new minerals, but apparently also that body was neglected.

Some alloys in the Cu-Zn phase diagram have considerable homogeneity ranges, see for instance
[el.wikipedia.org]
or
[pwatlas.mt.umist.ac.uk]

"zinccopperite" and its various spellings has a unique Chinese name which literally translated as "zinc copper ore". This already intimates that it does not have to have a unique version from the perspective of the Chinese mineralogists. The "zinccopperite" from Sanchakou is Cu2Zn, from Xifanpang is Cu7Zn4 and from Kelatongke is Cu3Zn. They also vary in their structure. So there are three phases for this name. ""Tongxinite" is used only for the Cu2Zn phase. I have more references than those given by Ernst if anybody wants them (although some are in Chinese only).

Cheers,

Jeffrey

Hi Jeffrey,
I'd like to see the references.

Thanks,
Jim

Jim,

I have added a long list of references to the Tongxinite and Zinccopperite pages a while ago - should be pretty complete. See also the list references in my original post.

Thanks, Peter.

LANG ZHIJUN. (1990): Zinccoperite (Cu2Zn) discovered in quartz diorite at Sanchakou, Hami, Xinjiang. Xinjiang Geology 8 (3), 274–278 (in Chinese, English abstract).

LUO MEI AND WANG YUEWEN. (1999): The discovery of copper-zinc (Cu2Zn) ores of Baxi gold deposit in Roergai and its geologic significance. Acta Mineralogica Sinica 19 (1), 20–22 (in Chinese, English abstract).

Dear Jim,

These references are not mentioned above. Hope they are of use.

Cheers,

Jeffrey

SHUAI DEQUAN, ZHANG RUBO, LUO MEI AND ZHANG JINGWU. (1998): The study of natural Cu-Zn series mineral—Tongxinite. Acta Mineralogica Sinica 18 (4), 509-513.

XIAO YANFU, SUN YAN, LU YAN, WEN CHUNQI AND WANG JIANGZHEN. (1998): An unusual mineral discovered in a porphyry-copper deposit — Zinccopperite. Acta Geologica Sinica 72 (3), 288 (in Chinese).

XIAO YANFU, SUN YAN, LU YAN, WEN CHUNQI AND WANG JIANGZHEN. (1998): Zinccopperite—a new variety of zinc-copper intermetallic compounds discovered in a porphyry-copper deposit. Acta Geologica Sinica 72 (3), 308–313 (in English).

XIAO YANFU, SUN YAN, LU YAN, WANG JIANGZHEN AND WEN CHUNQI. (1999): The discovery of zinccopperite in porphyry-copper deposit and its genetic significance. Science Bulletin [Kexue Tongbao] 44 (2), 37–38 (in English).

Thanks, Jeffrey. Are copies available?

I just received a PDF of:
Xie Yuling, Hou Zengqian, Xu Jiuhua, Yuan Zhongxin, Bai Ge, and Li Xiaoyu (2006): Discovery of Cu-Zn, Cu-Sn intermetallic minerals and its significance for genesis of the Mianning-Dechang REE Metallogenic Belt, Sichuan Province, China. Science in China, Series D (Earth Sciences), 49(6), 597-603.

if anyone is interested.

The authors mention that they use 'zinccopperite' specifically for Cu₂Zn. because it was used in an earlier 2003 paper. Of course, that paper used 'zinccopperite' for Cu₃Zn, Cu_6-7Zn and Cu₂Zn. One interesting sentence; "Most of the zinccopperite minerals fall in alpha portion in Cu-Zn alloy phase diagram, but Danbaite and Zhanghengite are in gamma and beta portion respectively." The use of the plural 'minerals' is telling.

Zhanghengite is given as Cu₃Zn, rather than CuZn.

They do reference the 1998 Dequan Shuai et al. Acta Mineralogica Sinica reference abstracted in AM 85,264(2000), but do not use the term 'tongxinite'.

Oh, the use of 'jupiter' for Tin was somewhat confusing when first read.