Stone Blocks are unconventional building blocks with 4x the mass of a normal Hull block of the same volume with no associated functionality or upkeep. Stone blocks are primarily intended as structural base of asteroids. For that purpose, they come in all available materials, include different shapes available for Hull and Armor and have three variants - regular, Rich and Super Rich.
Regular Stone is associated with barren asteroids, large claimable asteroids and already developed Mines owned by NPC Factions. It costs 1 unit of material for up to 66.67 units of volume and returns pretty much nothing when mined.
Rich Stone blocks cost and contain 1 unit of the corresponding material per 1 unit of volume and are 50% more durable. All readily visible ore-containing rocks in the asteroid clusters are made entirely out of Rich Stone.
Super Rich Stone blocks cost and contain 10 times the materials of Rich Stone, but also nearly 6 times stronger. Hidden ore-rich asteroids, that can only be identified using the Mining System module installed on the ship, have the core made out of this block.
Since Stone is a readily procured material that require no processing, neither type of Stone blocks require any Credits to be constructed.
Due to its amorphous chemical structure, any Stone has nonexistent electric conductivity and as such acts as a natural isolator. This makes Stone blocks completely immune to damage dealt by weapons with Electric damage type, such as Tesla and Lightning Turrets and Fighters, and when hit will prevent any damage to Hull Points as well. Due to immense mass of Stone blocks, though, this benefit is difficult to use without incurring significant penalties to ship's overall mobility.
Stone Blocks has an additional and essential use in constructing Stations. Stone Blocks can be used as extremely cheap source of Hull Points, that also inflates Station's total mass, which makes it resistant to collisions, outside forces and recoil.