Concrete

Concrete, stronger than stone.
Properties
Section	Powders
Spawn temperature	22°C
Heat Conductivity	40%
Relative weight	55
Gravity	0.3
Acid dissolve rate	0.2%
Flammability	0
State	Powder
Transitions
High temperature	above 849.85°C
Misc properties
Source code

Concrete is a heavy powder which can be built on top of itself into straight columns without crumbling. Nothing can move through concrete, no matter how heavy - including destructive bomb (concrete does allow gasses and liquids to escape though).

Creation

Concrete can be created with 1/25000 chance by taking molten rock and putting it under between 25 and 50 pressure.