If you have any Bloodstone Amulet in your bags, he will say that it belonged to his son. You may return it to him, if you like, but there is no reward.
Baldur's Gate: Enhanced EditionEdit
He doesn't give you any journal quest record, but if you have Colquetle's Family Amulet, you can return it to him for 250 xp and +1 Reputation. If you ask for a reward or refuse to give him the amulet: -1 Reputation, 250 xp.