Kovak's Workshop

On the edge of the map you'll find a small island with a tiny workshop. From time to time a zombie villager will spawn here. Bring a potion and a nice Golden Apple as a snack. In no time you'll meet Kovak and earn yourself the An Apple a Day advancement. He is able to change your gear to any type of material you want for the small price one Titanshard and a full block of said material.