Enlightened Fused Quartz
Enlightened Fused Quartz functions similarly to Fused Quartz, however it also gives off light like a torch. Enlightened Fused Quartz blocks connect textures when there are multiple next to each other. Enlightened Fused Quartz blocks are customized using Fused Quartz Frames.
see: Crafting Guide
To use fused quartz blocks in the default state, you simply place them in the world. Multiple Fused Quartz blocks placed next to each other will connect, producing a seamless window. To change the frame (border) of the fused quartz, you have to right click the Fused Quartz block with a painted Fused Quartz Frame, painted using the Painting Machine.