Per Fabrica Ad Astra Mod — Guide

Igneous Rocks

Igneous rocks are formed from the cooling of magma or lava. In PFAA, they are divided into Intrusive (cooled underground) and Extrusive (cooled on the surface).

Rock Type	Hardness	Distribution & Formation
Diorite	Very Strong	Bottom of continental crust, above gabbro; found as intrusions.
Gabbro	Very Strong	Bottom of felsic crust, oceanic crust; found as intrusions.
Peridotite	Very Strong	Found as deep intrusions.
Granite	Strong	Dominant in continental crust; found in large domes.
Pegmatite	Strong	Found as veins within granite formations.
Carbonatite	Weak	Rare, short vertical veins in continental crust.
Andesite	Strong	Found above granite in felsic regions.
Basalt	Strong	Found above gabbro in oceanic crust; forms shield volcanoes and islands.
Rhyolite	Strong	Found at the top of felsic formations.

Sedimentary Rocks

Sedimentary rocks are generally found near the surface and are formed by the accumulation of mineral or organic particles. Many of these are 'Weak' and yield rubble when broken.

Rock Type	Hardness	Distribution & Formation
Breccia	Weak	Localized continental deposits, often folded.
Claystone	Weak	Localized continental and oceanic deposits.
Conglomerate	Weak	Localized continental deposits.
Mudstone	Weak	Primary rock of the continental crust; also found in oceanic deposits.
Limestone	Medium	Common under the sea and in hills; resistant to erosion.
Sandstone	Medium	Found at the top of hills and mountains; resistant.
Coal	N/A	Generates in large beds; twice as common in swamp biomes.

Metamorphic Rocks

Metamorphic rocks are formed when existing rocks are subjected to high heat and pressure. They are typically found in the lower reaches of sedimentary layers or at mountain peaks.

Rock Type	Hardness	Distribution & Formation
Slate	Medium	Found in continental strata.
Schist	Medium	Located below slate; found in felsic mountains and oceanic crust.
Skarn	Medium	Found in both continental and oceanic crust.
Gneiss	Strong	Located below schist; often forms the peaks of alpine mountains.
Greenschist	Strong	Found near the bedrock layer.
Marble	Strong	Found in continental strata.
Hornfels	Very Strong	Found in continental strata.
Quartzite	Very Strong	Found in continental strata and mountain peaks.
Serpentinite	Medium	Found as veins throughout the crust.

World Generation & Geomes

The mod utilizes a custom generation engine to create realistic geological profiles. The world is divided into "Geomes" (geological biomes) which determine the sequence of rock layers from the surface to bedrock.

Continental Crust: Dominated by Mudstone, Granite, and Diorite. This is where most sedimentary and metamorphic rocks are found.
Oceanic Crust: Dominated by Basalt and Gabbro. These areas have thinner sedimentary layers, often consisting of Limestone and Claystone.
Mountain Peaks: Often capped with resistant rocks like Quartzite or Gneiss, while volcanic peaks are composed of Basalt or Rhyolite.