Gemspark Blocks

Gemspark Blocks are blocks that glow in low light only. The color of the glow depends on the gem used to craft the block. They are also mechanisms, as their glow can be toggled by wiring them to a trigger (though wiring them cannot force their glow to show up in higher light levels, and low light will still be required). Gemspark Blocks are crafted from Gems and Glass at a Work Bench.

Trivia

 * Diamond Gemspark Blocks are mostly used in pixel art, due the fact that the block is white and easily paintable.