Crude Onyx

Anyone have any Idea where i can farm for those like a good map. those are damn hard to get hand on but some ppl have so many. thx

go to sanctuary nexus...master mode...i avg 4-8 per run

+1 this, so many more drops from monsters on Master vs Abyss,
you can run any place that is above lvl 16 on Master and get lots of Crude Onyx,
but I tend to go to Sanctuary Nexus or the spider place (can't remember name)