#1 The glow effect on ice crystal wedge textures does not appear when their face is covered here

#2 seems if you add a solid block or wedge to the sloped side the crystal doesn't look like it emits light although the surrounding hull still receives the blueish glow.

NOTE: When a star shines directly on them they look just fine but with the star at the back you get this effect even though crystals should emit light from themselves.

#3 a block above the wedged side, blocks the emitted light

with blocks above

2 removed as exsample