[A. G. Maisey]

I've got several keris with pendoks made from suasa, they're all what a jeweller here (in Australia) would call rose gold, I don't know what the purity of the gold in these pendoks is, I've never had it tested, but what I do know is that the colour of gold depends upon the way it has been alloyed, gold + silver = yellow, gold + copper = red, ie, rose gold.

About 20 years ago in Solo I saw a man who was widely regarded as the best craftsman in metal for keris related objects, making a pendok out of suasa, he didn't call it suasa, he called it " emas merah" = red gold.

I have a Balinese keris that is 100% old and 100% Bali, the hilt is yellow gold, the pendok is rose gold.

The place where gold is fabricated doesn't dictate the colour, it is the way in which it has been alloyed, and that can change depending on many factors. In fact, although the usual metals that are alloyed with gold are silver and copper, it is my understanding that upon analysis we can find other metals as well, such as tin, or nickel or even zinc --- maybe other metals too.

As to whether or not suasa is indeed gold, that is perhaps a matter of perception. My understanding is that there is an old law that dates back to pocket watch days in the USA, that gold of less than 14kt. could not be called "gold". So, legally, in the USA you probably cannot have 9kt. gold, but here in Australia jewellers do a pretty good trade in 9kt. gold.

Yes, 1karat = 1/24 of the whole.

In Central Jawa metal that only contains a little bit of gold, say 5kt. or 6kt is referred to as "emas muda" = "young gold".

Then of course we have pinchbeck --- but that's another story.

Edit
Just a further short note on gold artifacts in general, that have come out of Indonesia. Archaic gold artifacts are very valuable items, there have been a couple of finds of hordes of buried gold artifacts in Jawa, notably the Wonoboyo hoard that was found in 1990. From time to time farmers and builders find odd small and large pieces of gold. Almost invariably these small private finds are offered to dealers in markets such as Pasar Triwindu, in Solo.
Over the years I have often been offered such gold artifacts, a few have even been genuine, but the vast bulk of archaic gold artifacts, including death masks and royal paraphernalia, that is offered for sale in Jawa are very skillful forgeries.
This raises the question of how one is able to detect such a forgery. Well, it helps if happen to know the dealer and/or the forger very well.