Antique Moro Gunong

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.

20th February 2018, 08:47 PM	#25
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,361	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.