From Starbounder - Starbound Wiki
Ancient Block is an object unobtainable by players through normal means. This item's information is present in the game files, but not intended by developers to be in players' possession.
Ancient Block is a construction block.
|Floran :||Ancient blocksss.|
|Glitch :||Amazed. These blocks are evidently very old.|
|Novakid :||These blocks are older'n dirt.|