I think I agree with Scras'. Without more information for why/how it exists theres no reason to use it. I'm not sure theres even that huge of a different between the weights and properties of gold and silver for it to make a big difference. Why not use silver? why not use gold? It makes an interesting flavor addition, but I don't really like it.
Brings to mind the Star Trek, Gold Pressed Latinum. Which I know it isn't but that is what I was thinking the entire time I read that. I am not saying I don't like the idea. I can see its use to some small degree for flavor and fluff of some kind, but frankly I don't see this as a viable source for income. A lot of players I game with argue constantly about dividing treasure... how do you divide a precious metal that is two in one?
The using it against creatures that can be harmed by silver is a plausible idea but how to keep the metal wet while fighting it seems virtually impossible. It has a short merit but it needs some more detail and work.
A good beginning but I agree with Scras and Pieh, it feels unfinished. It is an interesting bit of color, but without some other in-game use, it is unlikely to be included in any campaign. Some ideas about it's unique use or some other reasons to add it to a campaign would really help.