Minecraft wiki entry for Things_not_to_do, associated text: Ender chests drop only eight obsidian blocks when destroyed, meaning that the player loses an eye of ender. Ender chests never lose their items, as all ender chests are linked for each player. To avoid wasting eyes of ender, a player should use a Silk Touch pickaxe so the ender chest drops as an item instead of eight obsidian blocks.