Tsuba Material

[RobertM]

Picked this up a few months back. It was described as being made from Shibuichi. I was wondering if it is in fact just patinated copper due to the copper colour visible where the seppa have worn? In hand the tsuba is much darker than pics.

 

Many thanks 

 

Rob M

[Brian]

Shakudo is brass color and only gets its coloring from patination.

[Geraint]

Slip of the key board Brian?  My experience of shakudo is that it's copper colour before patination, no?

 

All the best.

[kissakai]

I have a similar one to Bob so interested in these replies

 

[Tanto54]

Agree with shakudo.

[Andi B.]

Unpatinated shakudo is copper coloured.

But it would be interesting to see the difference between black patinated copper and black patinated shakudo side by side.

 

But I'm not sure, how untreated shibuichi looks like with its high amount of silver.

Still like standard copper?

[Brian]

  On 9/3/2021 at 12:05 PM, Geraint said:

Slip of the key board Brian?  My experience of shakudo is that it's copper colour before patination, no?

 

All the best.

Expand  

Heck..I'm slightly colo((u)r blind. So what I mean is gold-ish coloured. Is there really a huge difference between copper and brass colour? Both are metallic gold-ish..opposed to silver colour.
I guess copper has a different hue, but my gist was it is goldish until patinated black.

[Andi B.]

(This shakudo piece is copper colored.)

[RobertM]

Additional shot

[1kinko]

Where to begin? There are several statements presented here as fact that are simply wrong. Ford is obviously the best person to make corrections but I’ll give it a try. 1) While there are chemical treatments that can turn copper black, they are not Japanese patina treatments. 2) Shakudo color depends on the gold content of the alloy and this changed over time. Older shakudo contains between about 1 and 10% gold, a trace of silver, and a trace of arsenic, the Ag and As being impurities. Some lead and iron are sometimes found. The shakudo I’m most familiar with is about 5 to 7% gold and is basically copper color but with a tinge of pink before it’s patinated. I’ve never seen brass or gold colored shakudo. 3) Shakudo does not have a high content of silver. Copper and silver make shibuichi and the color varies with the concentration of silver only after patinization. 4) Kuromido is an alloy of copper and arsenic that also starts out copper colored but turns dark brown to black when patinated.  However, kuromido does not acquire the “crow feather” black of shakudo. Hope this helps.

[RobertM]

Interesting read. So what would be the general consensus on what this tsuba is made from?

 

Rob M

[1kinko]

I think the initial information is correct, a relatively low silver shibuichi, maybe 5%.

[Ford Hallam]

To my eyes this tsuba would appear to be shakudo. Un-patinated shakudo is virtually identical to copper in colour. Shibuichi is, by comparison, a much paler pink colour before patination, but when the patina is worn off the bare metal tarnishes very rapidly to hid the fresh pale pink. Invariably what we see is a tone of grey, a more silvery patch sometimes (where the copper component of the patina has been lost leaving a silver rich film) or a dirty coppery/brass sort of tarnish.  I'll try and put together a little chart of images to illustrate the different alloys, patinated and not, to help in future identifications.

 

Copper alloys with less than around 10% silver patinate (in rokusho, the traditional method) to a deep chocolate colour, not grey or black. 

[Vermithrax16]

  On 9/5/2021 at 11:50 PM, Ford Hallam said:

To my eyes this tsuba would appear to be shakudo. Un-patinated shakudo is virtually identical to copper in colour. Shibuichi is, by comparison, a much paler pink colour before patination, but when the patina is worn off the bare metal tarnishes very rapidly to hid the fresh pale pink. Invariably what we see is a tone of grey, a more silvery patch sometimes (where the copper component of the patina has been lost leaving a silver rich film) or a dirty coppery/brass sort of tarnish.  I'll try and put together a little chart of images to illustrate the different alloys, patinated and not, to help in future identifications.

 

Copper alloys with less than around 10% silver patinate (in rokusho, the traditional method) to a deep chocolate colour, not grey or black. 

Expand  

If you stop back Ford, I just came into possession of a kozuka and the paper remarks the metal is "oborogin" which from what I can understand is shibuichi. Never seen a paper call it that though.

[Ford Hallam]

Hi Jeremiah,

 

yes, shibuichi is the least poetic of the alloy's names, and actually inaccurate in most cases to boot.

 

朧 銀 can be read as either Oboro-gin or Rō-gin , hazy or misty silver.

[andreYes]

Me too I have a similar one to Rob's 

I thought that it's shibuichi... 

I have another one, that I suppose to be made of shibuichi too, and its color is very similar.

I made a photo of the both. I think the goose is made of shakudo, the difference in color is obvious. So the plate is shibuichi, isn't it?

 

[1kinko]

I mis-spoke earlier and said I thought it was likely 5% silver shibuichi.  I should have said something more like 20% silver and I’ve worked with 20% silver shibuichi that patinates to dark grey with rokusho, but without the shine of shakudo. But there are also variations of shakudo both with the amount of gold and the amount of arsenic (and probably everything else).