Minecraft wiki entry for Diamonds, associated text: The player should mine with the Fortune enchantment on a pickaxe, preferably level III, for the next diamond blob, to significantly improve the number of diamonds they get. Also, this is not something they can rely on, but they can try. If they find a large diamond blob, they have an enchanting table, and are confident they can get a Fortune III, it might be worth waiting and acquiring the diamonds later or mining it with a Silk Touch pickaxe and harvesting the ore when they acquire Fortune III. If they see the hint on the table say Fortune III, immediately enchant a diamond pickaxe with it.