http://monsterhunter.wikia.com/wiki/Firestone

fire stone is in the volcano area 9-10.

or you can send Trenya to the volcano for 500 points, although going to the volcano
yourself, or better yet do them both

true, but it takes chance for trenya.

just take pickaxes to volcano gathering quest in 4* village cheif go to the top area i
think it's 8 and mine in the most ne point. there are 2 spots in the ne but u want the one
closest to the wall of smoke (i am not refering to the smoke in area 6 but i cant remember
wats in area 8)

i wear the golden rathian armor and get things easier that way. it works for me.

i get it... ur boasting. but what if i tell u that i have more than 10 armor sets that has
higher rarity than 9.

i can't find it ... >:( i mined evrywhere

firestones are always gotten from volcano....its not as hard as u might think

Trenya pay him 500 whatevers and you will get firestones soon enough, might take a couple
times, but i can assure you, you will get them