Bubblesofearth wrote:Jeez, have they never heard of Archimedes? Gold plated tungsten would have be more difficult to detect.
For gold coins - simply measuring the size (diameter and thickness) and weight along with a ring test (balance the coin on the fingerprint of your index finger and tap with another coin - and it should ring rather than being a dull thud) is 'good enough'. Tungsten content could meet the size/weight properties, but will fail the ring test.
There are pocket sized 'devices' such as https://www.thefisch.com/howitworks
- but a basic £15 vernier caliper and £20 electronic scale does the job. The fisch is just a modern day version of the sovereign/half sovereign testers that were around in Victorian times
When you have electronic/accurate scales you can also perform a specific gravity test relatively quickly/easily https://youtu.be/vYkfIAk8AMI
India/Asia has much greater interest-in/ownership-of gold as faith in domestic paper currencies can be a lot lower. Bitcoin falls into that 'dubious' potential vapour-ware category IMO.
Physical gold also doesn't have to be physically conveyed for instance from one country to another and can also be electronically transferred relatively easily - i.e liquidate into currency and electronically transfer that currency to buy physical gold at the desired target destination. As such bitcoin is more for those that perhaps don't want to leave a trail - which is more usually due to illegal reasons. Better to have a full audit trail and accountability of physical gold or otherwise be at risk of confiscation on the perceived belief of being the proceeds of illegal activities.