Seeds for Bronze, Compressed Iron, Constantan, Electrum, Elementium, Enderium, Fluix Steel, HOP Graphite, Invar, Lumium, Mana Steel, Refined Glowstone, Refined Obsidian, Resonating Crystal, Signalum, Sky Stone, Steel and Terrasteel .
The most of then i think for tier 5 or 6 .

Seeds for alloys are disabled to encourage use of other automation methods.

Then a seed for sky stone or another recipe for this block :) it´s the best black block.