Nice honeycomb you left there!
Once you have gem (especially diamond) hammers mining diamonds becomes much easier. I think the hardest part is trying to find them using pre-gem tools simply because of the time it takes to mine a large enough area 1block at a time.
When I started digging on Andooweem, the only diamonds I’d find were the occasional one at the end of coal or iron seam that I was mining out. Also, it was often 2blocks away from my tunnel -so close and yet so far.
So, being an optimiser, I found a quick way to expose as many blocks as possible using iron tools.
Start out with your atlas, getting down to around lvl 8-10 inside a hotspot, and dig a 2 high room about 20x20. This is the slow part.
Now, you are sure to find all the gems in this area but it takes a long time. My tip is to find all gems in the 3 layers above- you dig up straight vertical tunnels in an offset pattern, meaning that the sides of the tunnels expose every block as far up as you can reach like this:
XXOXXXXOXX
OXXXXOXXXX
XXXOXXXXOX
XOXXXXOXXX
Sorry screenshot not available this week.
It’s the pattern that knights (horsies, ♘ ) move in chess, two forward one left(right). As long as you pick either left OR right, then repeat indefinitely.
Each tunnel exposes the 4 squares next to it, no 2 tunnels expose the same block twice and no blocks get skipped. This gives 100% exposure for 20% mining.
If you’re done with your level, you can extend your room and carry on, or build a staircase to make the top of your tunnels the floor of your next room (about 4-5 levels up) and repeat.
Just a hint to speed up strip mining before gem tools