Bought a couple of Stormin Norman Silver rounds, Desert Storm. Support those who serve our country. They don't ring like a morgan does. Is it silver, or counterfeit? Can't imagine.
Your paper background is somewhat mauve in color, was it originally white? The reason is that the color of the coin and the toning/chemical effect resembles copper coins. Jim
Lay the specimen on a table cover it with a 1 ply tissue if you can see the coins though the tissue it's silver if not it isnt.
Your bullion coin is .999 silver, A Morgan dollar is .900 silver. Just that can give it a different ring. Say nothing about diameter and thickness.
Due to the fineness of silver composition with the other metals that make up the item and it's size, they will sound differently if you try and ring them. It's only my opinion and I know what you're getting at, but silver makes a distinct sound whereas crystal rings.
Does pure silver ring ? Yes. But it will be a slightly different sound than that of 90% silver. Now if what you're saying is that what you have there does not ring at all when you flip it, then I suspect it is not silver. Either that or you're not flipping it correctly - but I honestly can't imagine how that could happen. I say that because when a coin is flipped the ring sound you hear is produced by the impact of your thumbnail against the coin.