Antique Moro Gunong

[David R]

Red brass, what we call gilding metal in the trade..... could be. I forget about this alloy sometimes, and suwasa/swassa would probably not patina like that.

[Sajen]

Originally Posted by David R

..., and suwasa/swassa would probably not patina like that.

Even gold receive a dark patina over years and I've seen suassa very patinated which show only after a polish what it is.

Regards,
Detlef

[Sajen]

Originally Posted by Sajen

Even gold receive a dark patina over years and I've seen suassa very patinated which show only after a polish what it is.

The first picture show antique Indonesian finger-rings from high quality gold but patinated since for years not worn and second picture show a tested suassa pendokok which I received not only broken but as well dark patinated.

[kai]

Hello Detlef,

Thanks for the pics! I wasn't directly referring to your posting and my wording possibly wasn't clear enough.

I believe in these cases it's more like build-up of oil and dirt rather than typical patina. Still lower gold/silver alloys will also result in some oxidized metal, so this POV will be open to debate.

Regards,
Kai

[kai]

P.S.: Out of active use is the key word here, I believe.

[Sajen]

Originally Posted by kai

P.S.: Out of active use is the key word here, I believe.

Yes, I think this is correct!

[Rafngard]

First and foremost, what a lovely gunong! And I wish I could do half as good of a cleaning job.

Secondly, the "belt loop" on the scabbard is unusually isn't it? I don't think I've seen one like this on an older one before. Is this maybe a latter addition? The color of the metal of matches both the metal bands and the ferule/guard, so if it is latter, it's a good match.

Thanks,
Leif

[Sajen]

Originally Posted by kai

I wasn't directly referring to your posting and my wording possibly wasn't clear enough.

Hello Kai,

no worries, my post wasn't meant regarding your comment. Oxidation is transfer from electrons from chemical view. And even gold do it but extremely slow. And suassa has a lower gold content so it will patinate more fast. I am not a chemist but think that this is correct.

Regards,
Detlef

[Ian]

Originally Posted by Sajen

Even gold receive a dark patina over years and I've seen suassa very patinated which show only after a polish what it is.

I agree Detlef. Alloys with small amounts of gold can certainly oxidize, but I think it is the copper or silver components that are most affected by the oxidation. Many years ago I had a N. Thia/Lao knife with a copper/gold alloy sheath that was almost black with oxidation when I got it. I was very surprised when it polished to a rose gold color and had it tested for gold content. It assayed for a low gold content (I think 6-7% from memory). I coated the sheath with Antique Wax after polishing it, stored it carefully, and 15 years later that sheath has not tarnished again--still bright and a pinkish gold color. My guess is that it is a form of samrit similar to suassa.

Ian.

[kai]

Hello Ian,

Alloys with small amounts of gold can certainly oxidize, but I think it is the copper or silver components that are most affected by the oxidation.

Yes, in gold alloys it is the "lower" metals which oxidize while the gold is quite inert in such a setting.

However, alloys can exhibit quite a few funny/weird characteristics which need in-depth research to really appreciate them fully.

Regards,
Kai

[Battara]

I too Ian, my kris that once belonged to Datu Piang that has a solid suassa hilt (with solid yellow gold accents) was once black! I thought it was silver until I polished it and found the solid suassa.

What I base my leanings on the metal is the type of hue in its cleaned state, which looks to have less gold and more silver. Ian I think this is more like samrit than suassa.

Either way, it is a nice piece!

[Ian]

That's interesting Jose. For these non-silver black oxidized pieces, I wonder if there might be some arsenic also in the mix. Some oxides of arsenic can be very black in appearance. I seem to recall that arsenic has some mystical properties in mainland SE Asia--certainly some of the Hmong who live in the Twin Cities used arsenic for medicinal purposes and I was told by members of that community that arsenic is a powerful substance in their culture.

Ian.

[David]

That is a beautiful and elegant old gunong you have there Fernando. Amazing how many luks were fit into its 19cm length. Very nice work there. Also a very nice restoration on your part.

[kai]

Hello Ian,

as mentioned by Jose, most suasa also contains silver and it will be mostly silver sulphides contributing to any very dark patina.

For these non-silver black oxidized pieces, I wonder if there might be some arsenic also in the mix. Some oxides of arsenic can be very black in appearance.

At least the 2 common oxides of arsenic are white.

It's the arsenate salts with metals like iron that are blackish (cp. warangan). Metallic arsenic in an alloy is a quite different kettle of fish though and unlikely to be more than a trace contaminant...

I seem to recall that arsenic has some mystical properties in mainland SE Asia--certainly some of the Hmong who live in the Twin Cities used arsenic for medicinal purposes and I was told by members of that community that arsenic is a powerful substance in their culture.

Yes, arsenic compounds like realgar have been utilized in TCM (Traditional Chinese Medicine) for millennia and have a scientifically proven track record in modern medicine as well. However, there also are cancerogenic effects known...

Regards,
Kai

[kai]

Hello Fernando,

I'm with David in that suasa usually doesn't patinate that heavily during active use. However, if not handled for longer periods and with varnish/grime/whatever accumulating, it still is a valid possibility.

There are some quite unusual alloys with low gold and/or silver contents in Asia. IMHO it would be interesting to have it tested: Just make sure the jeweller understands that you're looking for (very) low gold content as this will influence the testing approach. Better yet, results from modern XRF instruments should allow a full understanding of this unusual alloy.

Regardless of the alloy utilized, a nice , early example!

Regards,
Kai