Not platinum or gold. Not Edwardian. Can’t determine if aquamarine/glass/synthetic sapphire/etc from a picture. It’s pretty and enjoy it.
Hi, very pretty but agree it’s modern not antique.
Setting is most likely Silver and the blue stone Blue Topaz and the purple stones Amethyst.
If you go to a jeweller / pawnbroker with a Presidium gem tester they can tell you very quickly if the gems are in fact glass.
Enjoy.