How to identify rocks with your phone

You probably have kicked a thousand stones in your life while you’ve been walking on the street or sidewalk and not thought anything of it. Driving over rocks on the road is something that happens every day millions of times. Nobody is going to carefully scan every single thing they step on, but what if you’re actually walking past something very valuable? What if you could find out if the rock you kicked or the one you spotted on the beach was actually worth something?