Buy from Scottsdale and you'll never get a counterfeit, also Apmex trains their workers and they have to be licensed to inspect each gold coin for authentication
gravity/density test, dimensions and weight test, and sound wave test are 3 out of four pillars. Having 4/4 tests is more than what bullion dealers do..... so good on you. I don't give much credit to ping tests.... neither do bullion dealers I think it's gold ;) 4x9s Queen's gold