There are old teachings which state that some keris were made out of a mixture of metals from 7 to 16 metals. I believe the teaching behind such statements have deeper meanings and not to be taken literally. I do however believe that there are some very special keris that indeed are made from an interesting and unusual alloy, specifically the material used to make the pamor.

The link to that yellow colour keris is interesting, the pitting reminds me of the same material as thogchag are made from. Basically a bronze to which ground up meteorite is added resulting in a pitted surface pattern.

Sorry Pusaka, but i can see no real connection between Caster's keris and thogchag objects. I am very doubtful that this keris contains any meteoric ore. I just spent some time looking at a large variety of thogchag objects on the web and can see little in common with the metal used in Caster's keris which is most probably a brass casting. There seems to actually be quite a variance of metal color and surface texture in these objects and they all look quite different from this keris.
Frankly i feel like this thread has travelled all over the place without really drawing much connection to the original question at hand, which is your pendok and why it may not show any signs of tarnishing. Certainly it is an alloy of some sort and metal alloys of various make-up have been used in this area of the world for quite some time. But the tangents here into the sonic qualities of various metals and gamelan gongs and the materials used to create Tibetan thogchags has brought us no closer to an answer about your pendok and has little to do with the subject of this particular forum. I would love to see us focus this thread more to the question at hand.

Well the answer as to why the pendok I have is not tarnishing must be that the alloy contains a metal which resists oxidation, I assumed it could be gold however it could also be nickel i.e. some type of nickel brass or bronze mix. My only reason for brining up the subject of Tibetan bowls is as Jean also stated they too resist tarnishing (the old ones) and as I have demonstrated this alloy is known at least in Bali.

All the subjects that have been raised are all on the subject of keris and metallurgy. I don’t mind the subject of unusual alloy keris blades being raised as I myself started this thread with similar statements that I had seen such a blade and buckle myself

As for Caster's keris, my belief still stands and yes it is fine to disagree with it.

Surely you can see that the color of these two metals are completely different and i know of no studies that would show that the surface pocking here is due to the inclusion of meteoric ore. The pocks on the thogchags is probably due to it also being a produce of casting. I have looked at dozens of thogchag objects on line that do not have these pock marks, so i am doubtful that they prove anything relevant to our conversation. But yes, it is also fine if you disagree with me. ;)
The subject of metallurgy in this forum is just fine with me when it applies to keris, but when we start getting off on tangents debating whether gold adds to the sonic quality of a gamelan gong or Tibetan singing bowl then as moderator of this forum i am going to make the call of "off-topic" and try to pull the discussion back to the subject at hand. I am personally very doubtful that the sound quality of you pendok is a valid issue here. :)

I am not referring to the colour of the two metals, obviously they will vary due to the ratios of copper to tin/zinc. I was referring to the pitting which is not caused by the casting process (why should it be) but due to the fact that there are impurities in the metal.

Meteorites are often dirty things and pitting is often the result. This pitting is often but not always observed in thogchag.

Now you have to ask yourself the question did the person who made that keris not have the skill to remove the impurities from that brass mix or did he add them deliberately, Personally I believe the latter

Why should pitting be caused by the casting process. Because air bubbles get trapped in the mold and leave pits in the surface of the cast. This is a well know effect of the casting process.

Of course meteorites are "dirty things". That is why you must refine the impurities out of them before you work with them. I have seen images of many blades forges with meteoric ore that have no pitting whatsoever.

Adding meteorite to this keris would not be adding "impurities". You would simply be adding another purified metal to the process. I am afraid that your line of reasoning here is making little sense to me and i see little use to all this speculation based merely upon internet photographs in furthering any understanding of the make-up of this keris specifically or keris in general.
I suggest that if you want to continue finding an understanding of the materials used to create your pendok that you try having it tested for various metal contents. Certainly it can be tested for gold or silver content. It seems that it has some metal in it's make-up that resists tarnishing, but what that is exactly will remain a mystery until you take the steps to find out.

Sorry pitting due to air bubbles do not look like that, there are too many and too close togeather.

Singing Bowls Gongs ETC Aside ...
 

To get back to the pendok, particularly the blewah example in post #13 as shown by Pusaka ... I have one of those, never really tarnishes; white brass I'd guess . :shrug:

We drift; do we not ?