How to Vein Mine Entire Ore Veins
Activating Vein Mining
When exploring underground and discovering a cluster of connected ores, you can harvest the entire deposit in a single motion rather than mining each block individually. Approach the ore cluster with an appropriate tool, such as a pickaxe, ready in your hand.
To trigger the vein mining mechanic, press and hold the tilde key (~) on your keyboard. Aim at one of the exposed ore blocks and hold down your attack/mine button while keeping ~ depressed.
Efficient Harvesting
Once the first ore block breaks, all adjacent, connected blocks of that exact same ore type will break simultaneously. The mined items will drop clustered together, allowing you to collect the entire vein instantly.
Keep in mind that excavating multiple blocks consumes tool durability for every single block broken in the chain. Furthermore, if your tool is enchanted with Silk Touch or Fortune, those enchantment effects are applied to every block harvested during the excavation. Always verify that your tool has enough remaining durability to handle the full size of the deposit before you begin mining.