I was attempting to assemble my own modpack for use with my wife on our little home LAN. While playing Gregtech 6.00.60, we noticed rather quickly that as opposed to Gregtech 5, Iron ore even in its cluster of Brown/Yellow Limonite, Malachite, and Banded Iron did not seem to spawn at all. Previously in Gregtech 5 caving for a while resulted in a few veins, as well as copper veins. However, in Gregtech 6, all I find is Talc veins and the occasional Redstone/Ruby vein. It's all Talc!
I have never even come across a small Iron ore vein. Magnitite spawns normally. I do have several other mods installed along side of Gregtech, but none of them were known to have heavy conflicts (at least from the documentation that I could find). I thought I had turned off all the world generation features for the mods leaving Gregtech as the sole ore generating source. I did leave Thaumcraft aspect's on though. I eventually broke down and tried to control ore generation via Custom Ore Gen.
ic2 version : 2.2.796
Gregtech : 60.00.60
Custom Ore Gen : 1.2.24
Forge : 10.13.4.1566
I do not have heavy experience modding, but I desperately want to play Gregtech 6, but it is frustrating not to know what I am doing wrong with regards to the ore generation.