The Freemasons are an extremely secretive society and will not divulge lists of their members,most of them won't even admit to being members themselves. Can I ask why you want to know...i'm a nosey cow.lol
I too know several Masons, they are not a secret society but they are a society with some secrets. In my experience if they can answer a question they will. So the best way to determine if someone is a mason is to ask them. In fact they had a series of open days in Dorset a few years ago where anyone could go on a guided tour round a lodge, they even published a Q+A session in the local Echo. There is a lot of Urban mythery that attaches itself but really they are not far removed from scouts for older guys! They do have some odd rituals though! No I'm not one!
Thanks all for your input. I have nothing against Masons and although not a member I've been a guest of friends at masonic social functions on a couple of occasions.I'm sure they do wonderful work. Someone I knew who was very elderly and frail made a large bequest to the Masons shortly before his death having had no interest or connection with them during his entire life. At the time he was being strongly influenced in other matters by an 'outsider' who also benefited substantially in the Will at the expense of his widow. Although everything was done legally his bequest was inexplicable and out of character.I can see no other rational explanation other than the outsider influencing his judgement.