Antique Moro Gunong

Sajen · 18th February 2018, 08:46 AM

Quote:

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 · 18th February 2018, 12:11 PM

Quote:

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 · 18th February 2018, 12:43 PM

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 · 18th February 2018, 12:46 PM

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

Sajen · 18th February 2018, 01:06 PM

Quote:

Originally Posted by kai

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

Yes, I think this is correct!

Rafngard · 18th February 2018, 04:45 PM

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

Ian · 18th February 2018, 05:31 PM

Hi Leif:

One does find older gunong with a belt loop like this, and it is not all that uncommon a finding. Often, however, the knife was simply thrust through a waist band and there was no need for a loop.

Ian.

Sajen · 18th February 2018, 01:01 PM

Quote:

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 · 18th February 2018, 05:43 PM

Quote:

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 · 18th February 2018, 06:01 PM

Hello Ian,

Quote:

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 · 18th February 2018, 09:38 PM

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 · 18th February 2018, 09:56 PM

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 · 18th February 2018, 10:57 PM

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.

Battara · 19th February 2018, 11:50 PM

That's a good question Ian. I don't know for sure. I know Bali uses arsenic in etching their keris blades.

One thing is for sure - often even the copper/gold mix of suassa has some silver content in it so that it won't become too brittle to work. Although copper is incredibly soft, when mixed with other metals it makes the new alloy brittle.

Also, some used the silver/copper alloy in a particular mix to LOOK like copper/gold suassa (especially since gold is so expensive).

kai · 20th February 2018, 06:31 PM

Hello Ian,

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

Quote:

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...

Quote:

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

Ian · 20th February 2018, 08:47 PM

Thanks Kai.

Yes, it's arsenates [–AsO4(-3), etc.] not oxides of arsenic [As2O3, As2O5, etc.] that are black.

I'm not sure that silver oxidation explains the intense black oxidation that I observed on my samrit covered daab. Some time ago I was sent an old formula for samrit, and no mention was made of silver in the mixture if I recall correctly. Also, the intensity of the black color was much more than I see on silver covered pieces from the same general region--silver oxidation tends to be more grey than black.

I have another Lao daab from the 17th C with a samrit hilt that has virtually no oxidation, and I have no explanation why one would have such a dark patina and the other virtually none. Presumably it reflects different components in each sample of samrit.

18th February 2018, 12:43 PM	#3
kai Member Join Date: Apr 2005 Posts: 3,255	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

18th February 2018, 12:46 PM	#4
kai Member Join Date: Apr 2005 Posts: 3,255	P.S.: Out of active use is the key word here, I believe.

18th February 2018, 04:45 PM	#6
Rafngard Member Join Date: Jun 2015 Location: Minneapolis,MN Posts: 350	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

18th February 2018, 05:31 PM	#7
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,399	Hi Leif: One does find older gunong with a belt loop like this, and it is not all that uncommon a finding. Often, however, the knife was simply thrust through a waist band and there was no need for a loop. Ian.

18th February 2018, 09:38 PM	#11
Battara EAAF Staff Join Date: Dec 2004 Location: Louisville, KY Posts: 7,280	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!

18th February 2018, 09:56 PM	#12
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,399	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.

18th February 2018, 10:57 PM	#13
David Keris forum moderator Join Date: Aug 2006 Location: Nova Scotia Posts: 7,218	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.

19th February 2018, 11:50 PM	#14
Battara EAAF Staff Join Date: Dec 2004 Location: Louisville, KY Posts: 7,280	That's a good question Ian. I don't know for sure. I know Bali uses arsenic in etching their keris blades. One thing is for sure - often even the copper/gold mix of suassa has some silver content in it so that it won't become too brittle to work. Although copper is incredibly soft, when mixed with other metals it makes the new alloy brittle. Also, some used the silver/copper alloy in a particular mix to LOOK like copper/gold suassa (especially since gold is so expensive).

20th February 2018, 08:47 PM	#16
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,399	Thanks Kai. Yes, it's arsenates [–AsO4(-3), etc.] not oxides of arsenic [As2O3, As2O5, etc.] that are black. I'm not sure that silver oxidation explains the intense black oxidation that I observed on my samrit covered daab. Some time ago I was sent an old formula for samrit, and no mention was made of silver in the mixture if I recall correctly. Also, the intensity of the black color was much more than I see on silver covered pieces from the same general region--silver oxidation tends to be more grey than black. I have another Lao daab from the 17th C with a samrit hilt that has virtually no oxidation, and I have no explanation why one would have such a dark patina and the other virtually none. Presumably it reflects different components in each sample of samrit.