Hi tnx for the reply, i dont know the difference between AG and Wet Tantalum. I checked as I scraped them and I thought they were Wet Tantalum capacitors. they are quite heavy in comparison with the elektrolitic capacitors I gathered from the boards in one device like 600 grams.
I disasembled a tube. I asume its for the laser missile guiding system. and it has, in what appears to be, some solid gold contacts. besides the acid method, is there any chance to identify if its gold plated or solid gold?

I acquired recently field line tester and I disasembled one of them and it has a big potentiometer with lots of gold plated contacts. I know sometimes MIL or aerospatial devices has some parts with large content of industrial gold.
I thought ot acquire this device to test the thickness of the gold. is it any good?

https://www.ebay.de/itm/362949200000...UAAOSwU-pXrFeN