I saw this lot of Fake Peace Dollars today: You can see the auction here: https://www.ebay.com/itm/365893295375 The seller even shows the individual coins on a scale where the coins are under weight. I'm trying to draw attention to this to help others.
Looking at them, I don't really see any indications of them being counterfeit. Then again, by no means an expert on the subject. Where I do see a concern is the weights of 24 grams when they should be 26.7, clearly out of tolerance even for wear.
They all look absolutely fake. There is no silver patina at all. The designs are mushy and the toning/patina is exactly the same on all of them. These look like bad Chinese fakes.
I can spot those from a 100 yards! No need to even see the reverse. These all have the "Chinese patina".
Then this is an excellent educational opportunity for you. That "toning" pattern can exist on real coins, and counterfeits can fail to display it. But an awful lot of counterfeits are colored exactly that way. And, yes, 11% weight loss is basically impossible. Any real coin with that weight would either have been struck on a planchet so thin that the design wouldn't have been fully struck up, or would be worn so heavily that you couldn't even see a date. (I've seen >10% weight loss on minor coins, but never on a silver dollar.)
There now likely more fake peace and morgan dollars than there are real ones. Never underestimate the ignorance of the "general public". They won't know until they or their heirs take it to a pawn shop and find out they're worthless. In the meantime, they leave positive ebay feedback! hahahahahaha