User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-5043481-20140101113423/@comment-5270386-20140102124851

My advice is to equip the leather armour from the beginning of the game, get a gathering charm so that you have gathering+2, then start the G-Rank Deserted Island gathering quest and go mine in Area 4. Once you've mined all the nodes, run around the circle part of the area until you see one that has respawned. If you keep at this you can get 99 earth crystals in about 30 minutes.