A method called branch-mining is an efficient way to mine diamonds in Minecraft. Branch mining involves covering a greater surface area by creating a tunnel 2 blocks high and 1 block wide and digging individual “branches”. While this method sounds time-consuming at first, it can be really rewarding and you can get a significant amount of diamonds in just a few minutes.
Steps to branch mine:
- Firstly, mine down to y-level 11.
- Every 3 blocks, mine to the wall on your left and right as far as your player can reach without breaking the bottom part of the wall or any additional blocks.
- Continue to strip mine 3 more blocks and repeat step 2. Once you find diamonds, it is a good idea to check for lava above and underneath them.
Everyone can use their own way of mining diamonds, there have not been enough “studies” in how to mine diamonds, yet you did not limit the most efficient way of mining diamonds to anything, so I will answer in 2 ways.
The first way, the fastest way, is to use Baritome to automatically mine diamonds, going from source to source in the fastest, computer calculated way.
The second way, which is the user friendly way, is different, as said above, for each user, yet my method is, since most diamonds spawn on the levels 8 to 12, to mine a 5 block high tunnel on level 5 and have 2 blocks between each and every mining tunnel, leaving no space for diamonds to be missed on these levels.
The most efficient way I have found is strip mining. Although it can be tedious at times and can result in being frustrated for mining for a long time, the reward is worth it at the end. Coming from that, another efficient way to mine diamonds would be to just explore caves and clear out lava patches as they contain the most chance of having diamond usually.