Minecraft wiki entry for Advancement_guide, associated text: To get this advancement, you will need to obtain crying obsidian. Crying obsidian can be obtained from bartering with piglins, from finding it as part of ruined portals, or from loot chests in bastion remnants. You will need a diamond pickaxe or better to mine it. Once you have the crying obsidian in your inventory, you will be rewarded the advancement.