There is a bug in lunacraft that sometimes causes the player to end up inside solid rock. The bug can be exploited to see through solid rock. This makes it easy to find Blue_Crystal and Astronaut_lairs, among other uses.
Method
- While standing on the surface, look straight down and dig at least three blocks down.
- Now look up and place a block directly above your head. This block should be a solid material like Rock, not a transparent material like ice.
- Now look down again, and place a block at your feet.
You will now be "inside" the block that you placed above your head in step 2. The view will look strange, with most of the ground becoming invisible. You'll see sky (color if it's daytime, or black with stars at night) and various bits of terrain and probably some underground blocks. Here are a couple examples:
- The dark blocks seen here are underground deposits of Blue_Crystal.
- Some Gold blocks inside ice seen from below
Escape
Since your head is inside solid rock, you're trapped. To "escape", look in any direction and drill, which will remove the block that your head was in. You can do this even if you don't have a drill (if you are holding no object, press the action button to "punch" with your fist. It takes a long time, but eventually the block will be broken.).
If necessary, drill one or two more blocks until you can see where you are, then climb out.
Alternate methods
Instead of digging straight down, you can get the transparency bug inside any corridor that is two blocks high. Just look down and place a block at your feet, and you'll be pushed up into the ceiling.
The transparency bug can also happen in certain situations where you're jumping and/or walking into a block that is above empty space. See the article on One-way_doors for examples.
Credits
This method was originally described by Scooter8pie in a comment in the Blue_Crystal article.