In what form is the 500 grammes? 1 Half kilo bar - maybe a bunch of Perth Mint Certicards?... more than likely a bunch of 22-24k coins in the coin purse of your wallet? - I seriously doubt it as jewelry? - never You may look like a circa 1970's pimp... but carrying your wealth through customs as jewelry is the most hassle-free exercise in stealth you can perform. Remember it's not about being right or wrong..it's an argument you don't want to get into with those boneheads. "Don't wrestle with a pig..you'll only end up covered in sh!t and the pig will enjoy it" hey, I just realised you can't spell 'stealth' without using the word "steal"
I always carry a few sovereigns when i go overseas , for security. Just put them in your wallet with some 20c,and put that and your belt,watch. and change in the pan that goes to the side of the X -ray machine.Or in your carry on.Looks like loose 10c and 20c pieces. Good to have if your credit cards disappear or don't work.
Don't put a lock on your carry on hand luggage. They get suspicious when they see that. My girlfriend was going to check in all of her bags on a trip to Sydney but at the last minute decided to carry it on instead. It still had a padlock on the carry on bag. They asked, why she had a lock on your carry on luggage? Then pulled her aside to bomb check her. lol