I need to farm Ruby Orb

Anyone know how to farm this material?
I am 400 jeweler and i have a hard time finding.Sometime i can get it from gathering mithril (ruby crystal that i can change in ruby orb ) and orichalcum,but it is very hard to find.
Another way to get it is farm fire elemental mobs.The problem is i don't find the right level mob.I need fire elemental 70-80 but i found only 66-68 and they give ruby shard and low % of drop it.Every 4 ruby shards i can get 1 ruby orb.Anyone know a good spot of fire elemental lvl 70-80?or another way to get it fast?

why dont u try the auctionhouse? the prices are pretty low.

Press "O" Ingame.

u could try to farm orichalcum veins and orian saplings. sometimes u get orbs and with a bit luck u get ruby orbs. but I would recommend buying them, too. they become cheaper from day to day though.