I am stuck again!

[samcu]

Hello again,
I feel like a fool but I have to ask this cause I am stuck again...
Where do I find more Kathorn crystals?

spoiler



I need to use it to build the glasses to see the entrance of the wheel clan. I sold all those crystals cause I thought if they were important, they would worth more. Now there are none left and I have already been to many places in the map: Ashbury, Black Mountain, Elvin Burial Grounds, Tarant, Dernhelm, Anicent Temple, Ancient Maze and Black Root.

Should I just comb the area for more secret locations, or should I just check the walkthrough?

Thanks you the help (again)...

[samcu]

Found one in a Dungeon... thought this day would never come...