What is the best testing to prove a coin is pure good or silver?

[Deputydog]

Hi, I hope all is well.

I have recently bought some coins off eBay.

What is the best grading to prove they are pure silver or gold?

Thanks

Deputydog

 

[Clens92]

I'm not sure if 'grading' is the word that you are looking for; do you mean 'testing'?

Weight, thickness, diameter and the Archimedes test of water displacement are easy, everyday methods for authenticating silver / gold content.

XRF analysis is good - but expensive. 

 

 

[Deputydog]

Hi, my mistake, I do mean testing.

Thanks

Deputydog

[MickB]

Digital scales and vernier calipers to check the weight and exact size for starters. These are my first tests. If for example you buy from Bullion By Post, or most other dealers, they specify size and weight with the coins they sell.

If something raises suspicion then proceed to other tests.