Runic Stones can be found from the bottom of the world up to y level 2. When mined without Silk Touch they will drop a Rune.
Arcane Crystal Ore can be found from layers -40 to 14. These blocks luminesce, standing out against the darkness. This ore can be most commonly found at layer -13.
Can be found from levels -44 to 42, but it's very rare. Beware, this block is known to be very dangerous when you break it, mine it with some safe distance. Drops a Stellarite Piece.