Jewelers can 100% tell the difference between manmade carbonized human cremains diamonds and naturally occurring diamonds. Ive talked to my jeweler about it because I was considering doing it with some of my mothers cremains. He said the tell is a ton of minute debris in the cremains diamonds that are not present in naturally occurring diamonds. The debris is not evident to tthe naked eye, you need a jewelry loupe to see it. He said its a novelty targeting grieving people and no jeweler considers them real diamonds and the only worth is to the family member having it produced. Walmart is most certainly NOT selling something like that and trying to pass it off as a real diamond, they would be opening themselves up to a lawsuit for fake advertising.