First put potions in all of your quick item slots.Now switch to the inventory screen and replace the rightmost potion with a gem. Now return to the adventure screen. Notice the picture of the potion you replaced with a gem still looks like a potion. Click it multiple times and return to the inventory screen. The number of gems should change from 1 to no number at all. Switch back to adventure screen and repeat the process...now you should have 65,000 gems.