I received my lost jewels when the Post Office finally got the bright idea of actually sending them to the address printed on the package. So as promised, here's my review.
The large rectangular stones were purchased via Aliexpress from cshine rhinestone & jewelry Co.,Ltd. I bought the 13x18 rectangular stones in gold claw settings, in the Black Diamond color.
These stones are gorgeous. They have just enough sparkle to look impressive without being too gaudy. The color doesn't show up well in the picture, but it's a deep gray.
The gold claw sew on setting is stamped from very thin metal, so I wouldn't count on the claws being terribly strong. I may pop all the stones out of the settings and add glue just to be sure.
The smaller stones are hot fix "imitation DMC" rhinestones from ArtCentury Official Store, also via Aliexpress. I say imitation because the original DMC (Diamante Machine Cut) rhinestones are made in Korea. These are probably made in China and are of lower quality. They are only moderately sparkly, which is okay for my project, but I wouldn't use them for something that needs a POW! of sparkle.
The hot fix glue is basically worthless. I did tests by hot tooling them on both synthetic satin and cotton, and let them sit for 24 hours. I was going to test how well they stood up to being washed and dry cleaned, but when I nudged them gently with my finger they all popped off. Luckily, I've decided to glue my stones to filigree bases, so this isn't a problem for me, but next time I'll just order non hotfix backs.
So, my conclusion is that the sew on large jewels are good, especially since they're virtually unobtainable anywhere else, but the rhinestones are only suitable if you don't need a lot of sparkle and don't need hot fix.