Minecraft wiki entry for Diamond_Ore, associated text: The diamond ore block itself (rather than its diamond drops) can be obtained by mining it with an iron, diamond, or netherite pickaxe with the Silk Touch enchantment. When mined without Silk Touch, diamond ore drops a single diamond. The maximum amount of diamonds dropped can be increased with Fortune. Fortune I gives a 1⁄3 chance for 2 diamonds, averaging 1.33 diamonds, Fortune II gives a 25% chance (each) to give 2 or 3 diamonds, averaging 1.75 diamonds, and Fortune III gives a 20% chance (each) to give 2, 3, or 4 diamonds, averaging 2.2 diamonds.