Totally normal, took me for freaking ever to get that drop. Just ran around tab targeting mobs and killing them. Found so many cleric pearls during that and those things were painful too.
Are you on a server where highsun is available? You can have a box or other player camp one of this known spawns and high sun everything you find until you can get him. Otherwise, pop a pick and rush over to see if he's there! That's all I have, good luck.
