It seems some participants on this thread need a quick primer on basic geology.
I haven't noticed who they might be, but it could be possible.
The only posters who have mentioned volcanoes are Corpuscles and myself.
The main type of stone being discussed by myself is limestone which is a sedimentary rock.
Andesite is an extrusive igneous rock which forms from magma and flows to the Earth's surface under pressure often through faults in breccia.
Over to you.