This has nothing to do with stone vases as far as I can see.
What does that have to do with stone vases and vessels?
Good we are on topic. There are many ways the stone vessels could have been made. It looks like the Metropolitan Museum of Art has about 115 ancient Egyptian stone vessels, so they don't seem as rare as you thought.
I don't see any big issues with obtaining any vases or vessels to test, but I also don't see burning reason to test them anyways, what do you expect to find?
If you would like to buy one of these ancient stone vessels to test it, here is where you can buy one: Stone Vessels.