My nice place :D
Cartograph showed that I had a few little bits of iron right near my mine walls in various places, only little bits like 11 in the biggest case but it got me a full stack plus some armor.
Outside, from the wall facing away from the entrance:

Standing right outside the entrance looking at the wall:

Inside, main area. To the right you have the mine shaft entrance on the upper level and a public storage/crafting area on the lower level. To the right will be housing, once I get around to it, with a multitude of rooms pre-dug but not furnished. (Probably 8-10)

Main area, at the lower level. The art hung in the rear center of the room.
Considering that the big painting should have a secret tunnel behind it, but not sure how it'll act.

Main area, same spot but facing the entrance.

Dug almost entirely with stone tools. I still have two large chests of loose stone that I may one day smelt into solid stone and use to make a nice tower above it.
The mine goes down to lava, and is fairly extensive down there, but I've found no diamonds. According to the 5 slices I got done with cartograph before it just started crashing when I hit render, there's like two pieces of diamond about 30 units west of the westernmost point, and about a loving hundred south of there. That's the nearest. Two loving pieces. Gonna go mine somewhere else probably, and not make the mine far-reaching on early levels. Just me and four stacks of ladders.
After making the main room I swapped to peaceful. Seriously. A loving million spiders. Never a single creeper since I was always underground, just
fffffflovingspiderseverywhere no matter how well-lit my whole mine is. D:
And that sword is a waste of a pickaxe slot when I'm mining.