Lumite Rods are crafting materials that can be made in a Processor.
Like with everything else crafted in the Processor no recipes have to be unlocked for this.
Or 4 Lumite Rods can also be processed from 1 Lumite Slab each.
Lumite Rods are used for only a few crafting recipes, like for Lumite Roof and Lumite furniture (as of R26 in December 2015).
Lumite Rods are no blocks, so (currently as of R26 in December 2015) they cannot be put into the quick-bar, cannot be placed into the world and cannot be displayed on Wall Shelves, in Wood Planters nor in Flower Pots.