To reduce black money flying out of country , coins should replace notes since coins can be detected by x-ray.?

to reduce black money flying out of country , coins should replace notes since coins can be detected by x-ray. and will be heavier to feel. coins of rs10k,1k 0.5k etc to be made. this will also stop reprinting of notes and save money. cons should not be round otherwise i can roll off on the floor. may be hexagonal