Minecraft wiki entry for Nether_survival, associated text: Enchanting your pickaxe with Efficiency II allows you to instantly break netherrack, however mining netherrack too quickly can expose hidden lava that rapidly flows out and engulfs you, so if you do not have fast reflexes, it is recommended that you use unenchanted pickaxes instead. Other pickaxe enchantments useful in the Nether are Unbreaking and Silk Touch. Unbreaking can save you bringing multiple pickaxes (but again, you can choose to devote on quantity instead of quality, and just craft new pickaxes when you need them). Silk Touch ensures that nether gold ore drops the ore itself, guaranteeing you one gold ingot per ore block (instead of 4 nuggets on average with unenchanted pickaxe), as well as obtaining nylium, useful for farming Nether wood and foliage.