Note: All Icebrood mobs drop the Corrupted Lodestones, not just the Colossus' although I have never personally seen any other Icebrood mobs drop them so I can not confirm it myself.
This is probably the best farming location that I have come across while playing Guild Wars 2. Corrupted Lodestones are used in crafting Legendary weapons amongst other things and sell for almost 1g each. And despite them being rare items when farming at this location with enough Magic Find you can still find quite a few of them every hour. I usually find at least one an hour from farming here but drop rates have been reported to be all over the place. As with everything when it comes to randomness, things will be random!
Keep in mind all Lodestones can be farmed in WvW zones, however I will not go over their locations in these guides as ganking will be a large factor when it comes to farming in WvW related zones. And who wants to deal with ganking when you can farm without it?
Now the most important thing you should know about farming this location is, well, Magic Find! Stack any little bit of Magic Find you possibly can on your character. Buy the highest Magic Find food (Omnomberry Bars) and be sure to use your Magic Find gear while farming here to increase your chances of finding a Corrupted Lodestone as much as possible. Something I cleared up in my video of this farming location but will do again here is I heard rumors that you need over 100% Magic Find to farm these Lodestones. This is a total lie.
I have 95% Magic Find and found 3 of these in my first 30 minutes here and an additional two over the next 30 min I was here. That's about 4g an hour without even counting the other items I found! Now you've probably heard of Anets diminished return when it comes to farming to try and stop botting. This can be a problem when farming this location so for that reason I recommend you only stay here for about an hour before changing zones or maybe just running around Frostgorge gathering all the goodies before coming back.
Aside from the amazing amount of money you can earn in this location every hour you'll also know when Jormag spawns as long as you pay attention to map chat and also it's very common to see Orichalcum spawn around Ice Floe waypoint, which will be a bonus 9s every 24hrs for that Orichalcum node. And hey, say you're porting in to Ice Floe waypoint just for the Orichalcum, why not clear out all the Icebrood after you gather your ore for a chance of a Corrupted Lodestone? Give it a try!
Anyway aside from the Lodestones you'll also find stuff here like Large Claws and Vicious Claws, both are Fine Crafting Materials used in numerous different recipes. Aside from that you'll also get some salvage items as well as blues, greens and sometimes even a rare you can salvage for a Glob of Ectoplasm. But you probably already knew that. On that note, good luck at this location and happy hunting!