Are These Dutch Rijksdaalders Authentic?

I'd pass, even cheap.

Photos aren't good enough to be absolutely certain, but at least two are fakes and the rest probably are too.

thq, kindly elaborate on this Halo toning.

They look like Chinese fakes I have seen recently on e-bay.

Best solution is find a real benchmark prime example and first examine details, colouration and then reeding this is the most foolproof way for low value (less than a couple grand) coins especially these days, as Chinese have bad quality controls there more worry about quantity (1 sucker buying 100 of these imagine). Then weigh and test with magnetic, note these test arent the best method in my opinion. Last you can test silver test such as tap or blow test or ice test, unless its a unc or xf.

with the halo darking/toning not a good sign as many Chinese fakes especially have fake/darking wear on to make them seem old and valuable.