I agree that it is a good thread, and important for stackers. It's interesting that the only good tungsten fakes I've heard of are 22K. My guess is that 24K is harder to fake due to the higher density.
The crooks are getting better and better at producing these fakes. I have watched a few fake 10oz gold bars that were filled with tungsten. It seems they are now doing smaller coins and bars. Best to buy from reputable dealers. I have heard of XRF failing but not ultrasonic