Rock Hound and Repair

Off the shores of the Steppes at the Siren Temple, I had a run in with a siren, and after our struggle I recovered a tarnished silver necklace inset with agate. Some of the agate is missing and I've decided to try and find some agate that matches what is in the necklace already and repair it. 
==Steps==
#Kill any of the various rock heaps (lvl 25, 26, 26^^, 27, 27^^^) along the Dead River for 4 agate stones updates
==Rewards==