I did 100 Pokestop ( i counted <.< ) and no stone :c So the chance to get a stone from Pokestop is 1% or lower ?
Yeah, you gotta realize that there are thousands of people that use pokestops consistently and if they are common, their value would diminish tremendously. In the grand scheme of things though if you are active and play often it's not very hard to get one. So good luck