山銅 Yamagané and 山金 Yamakin

[Bugyotsuji]

This Tsuba was described as “Yamagané, not Shinchū” (i.e. not brass).

 

Having looked at many examples of 山銅 Yamagané though, they generally seem to be more of a dark reddish brown copper material.

 

There was also 山金 which is to be read Yamakin (although many people read this Yamagané, mistakenly?)

 

Are we aware of these differences in the namings, and what are your thoughts on the material of this hexagonal Wakizashi Tsuba? Seems yellower than brass. Note natural/artificial (?) mottling on surface.

Thick, flat, rounded mimi.
7.2 cm x 6.0 cm x 0.45 cm.

 

 

 

 

[Bugyotsuji]

PS This quote may be describing the difference between Yamakin and Shinchū but without a background in metallurgy my comprehension rate is sluggish at best. Higo metalworker artisans liked working in Yamakin, it mentions.
肥後金工が好んで使う「山金」は、素銅に鉛・砒素・アンチモンなどの他の金属を混ぜた合金で、銅山から産出されたままの銅では無く使用目的や色合いを考慮して配合工夫されています。
　話は変わりますが、銅の合金である真鍮（黄銅）も、銅と亜鉛の配合比率によって色が違ってくるということです。

From a discussion on copper, here:

https://ameblo.jp/o-deco-3/entry-12170960771.html

 

[Bugyotsuji]

For reference, I have seen this kind of ‘Nagoya’ Tsuba described as 山銅Yamagané.

 

 

 

[John A Stuart]

I can't reconcile the brassiness' of the hex tsuba, however the fact that shinchu is copper and zinc and yamagane is arsenous, lead or antimony with copper seems perfectly succinct, as in brass and bronze being different.. John

[Matsunoki]

I’m sure Ford (hi again Ford…long time!) will tell us more but from my experiences in Japanese Meiji metalwork (and as I’m sure you all already  know) the Japanese were masters of creating alloys where even the smallest variation in their compositions can create a vast range of different colour nuances when put through the same patination processes. Given that Meiji metalworkers inherited most of their skills and knowledge from sword fitting makers it is reasonable to assume the “soft metal” tsuba etc makers utilised nearly the same variety of alloys. I guess the only way to be sure is to have it analysed by one of those “magic scanner guns” that can accurately measure the metallic element composition.  The tsuba under debate could be an alloy that I have often seen called Sentoku. The surface looks as if it may have been created using an etching technique and it may have lost its original patina which causes further confusion!  Just my thoughts.

[Bugyotsuji]

Thank you John and Colin. This is all grist to the mill. 
 

Step by step one gets to Rome.

[SteveM]

A lot of these terms sit at the intersection of linguistics, metallurgy, and history, and dealers aren't always faithful linguists or metallurgists. It doesn't help that there are multiple, often confusing, ways of naming metals. I'm sure Ford and Markus have already spent many hours unravelling these linguistic knots.

 

I think the tsuba in this thread was probably described reasonably accurately as yamagane (山銅), or unrefined copper. I can't imagine it being unrefined gold unless it comes with a hefty price tag. It could have been treated with something to make the color pop. 

 

Sentoku (宣徳) and shinchū (真鍮) both refer to brass. Sentoku is a kind of brass that was imported from China into Japan during China's "Sentoku Era" (1426-1435). The era name was stamped on brass bowls and such, so the Japanese started referring to all imported brass as "sentoku". The word "shinchū" starts showing up in the 1500s, again from Chinese imports. Shinchū was a brighter, more refined brass, with a higher zinc content. Looking at a few websites though, you find there is little consensus on the exact amount of zinc used in shinchū. It seems to refer to anything over 20% zinc, but there are dissenting opinions on this.

 

Anyway, I leave some Japanese references here for yamagane, shinchū, and sentoku in case anyone wants to dive deeper. Or, if anyone has any contradicting info, I would be interested in that as well. Might be interesting to start a thread for Japanese metallurgic terms, if there already isn't one. All of these terms can drive a translator nuts. 

 

all in Japanese

https://mitsu-ri.net/articles/brass (overview)
https://www.dandorie.com/c10110103/39_cont_shintyuu.html (very readable account)
https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-18H03591/  (current academic research)
https://sot-web.com/column/brass/ (another overview)

 

 

 

 

 

 

 

 

[ROKUJURO]

Piers,

the structures on your hex brass TSUBA are probably caused by segregation, not by a treatment after the production process. I read this can occur naturally as an effect of casting, and it may show different forms. Aging can enhance this.  

[DirkO]

yamagane (山銅), lit. „mountain copper“): The term „yamagane“ describes raw, unrefined copper, whereas during the Edo period, sometimes relatively pure but already smelt copper was also called yamagane. Until the Sengoku period, the term yamagane was synonymously used for copper which came directly from the mines. This copper varied strongly in colour according to the area of mining. According to analysis, yamagane contains lead, arsenic, and antimony, and this is the reason why it is harder and darker than pure, refined copper. Early yamagane pieces like tsuba or kōgai appear subtle and plain, but this makes the special aesthetical sense of yamagane.
Important to note is that copper or rather its patina changes over the centuries, therefore dull and darker copper pieces are not necessarily made of yamagane. So one has to be careful when examining and judging sword fittings.

 

Above excerpt from Markus Sesko's Handbook of Sword Fittings

[Bugyotsuji]

Showed this hexagonal Tsuba to a well-respected metalworker from Osafuné today and he said:

“Ō-dō or Shinchū, probably Edo Period. Quite unusual. The alloy ratios varied tremendously. The surface has been acid etched.”