Antique Moro Gunong

Ferguson · 17th February 2018, 08:21 PM

Very nice sir!

David R · 17th February 2018, 08:31 PM

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 · 18th February 2018, 09:46 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, 01:11 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, 01:43 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, 01:46 PM

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

Sajen · 18th February 2018, 02:06 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!

Sajen · 18th February 2018, 02:01 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, 06:43 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, 07:01 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, 10:38 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, 10:56 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.

kai · 18th February 2018, 12:41 PM

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

18th February 2018, 12:41 PM	#13
kai Member Join Date: Apr 2005 Posts: 3,255	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 Last edited by kai; 18th February 2018 at 01:37 PM. Reason: clearer wording

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17th February 2018, 08:21 PM	#1
Ferguson Member Join Date: Dec 2004 Location: Kernersville, NC, USA Posts: 793	Very nice sir!

17th February 2018, 08:31 PM	#2
David R Member Join Date: Jan 2011 Posts: 1,145	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.

18th February 2018, 01:43 PM	#5
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, 01:46 PM	#6
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, 10:38 PM	#11
Battara EAAF Staff Join Date: Dec 2004 Location: Louisville, KY Posts: 7,368	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, 10:56 PM	#12
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,649	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.