When I'm not exploring fresh caves or lands in minecraft, I'm busy trying to find deposits of diamond, gold and iron deep in the earth. So far I've just been digging around just above bedrock on a whim to look for these rare minerals but I've started thinking that I should be taking a more controlled, efficient approach to mining.

**What is the optimal mining strategy that yields the most rare minerals while minimizing blocks removed and time spent digging and traveling?**

**Edit:** The existing answers are great for mining, but no one has addressed travel time to and from the mine which is usually ~60 blocks downward and incredibly tedious. Solutions?
['https://gaming.stackexchange.com/questions/8310', 'https://gaming.stackexchange.com', 'https://gaming.stackexchange.com/users/1070/']
Referring to your edited question about the distances to and from your mine:

For the way down to my mines I usually use a minecart.  

For the way up, this would be a nice construction: [Piston Elevator](http://www.youtube.com/watch?v=WNGVwyARMyE)
i would like to add some (CREATIVITY) to the branch mining.

conventional branch mining is explained above. also in *seven sided die*'s answer there is mention that veins occur in **2x2 blocks**.

we generally think mining in term of 2d lets consider the third dimension.

[![made an illustration showing the method](https://i.stack.imgur.com/BYtoX.jpg)](https://i.stack.imgur.com/BYtoX.jpg)

(this is just an illustration) so the wool is to show that 4 spaces are left between corridors.

reason for leaving 4 spaces :-

* (Assuming that veins occur in **2x2 blocks**) the vein has possibility of appearing in center 2 block (out of 4 wool block i.e pink and blue wool in this figure) so it can be spotted while mining corridors on alternate floor (1st , 3rd , 5th, .....)
* same rule of possibility of spotting veins apply to corridor on (2nd , 4th , 6th, .....)
* the above shows the possible center block vein. block adjacent to cyan and maroon (in shown figure) can be easily seen so no doubt about that.

so this method reduces number of blocks mined and increases efficiency with respect to time.

**Key assumptions : veins appear in 2x2xX**(there is very very less probability of generating 1x1x1 vein ).