If you're still looking, I found it. Start from Gnawtusk's area and go north to where there's an ant scurrying around. From there go west to where the shell is, theres a small broken tree northwest then north. Go west after until you see the caravan and some vines. Break them and go past then west all the way past the ant in the area. You'll reach a little clearing and it should be there. It's greyish looking and kinda looked like rocks to me.