The issue comes up mainly in relation to the spell wall of stone, which states that:
A nonmagical wall of solid stone springs into existence at a point you
choose within range. […] The wall is an object made of stone that
can be damaged and thus breached. (PHB 287)
The wall is a nonmagical object from the moment it is created. This, to me, reinforces that it is ordinary stone, with all the properties of it. However, the spell unhelpfully neglects to inform us of many of its properties, in particular any damage threshold, resistances and immunities.
Objects are immune to poison and psychic damage. You might decide that
some damage types are more effective against a particular object or
substance than others. […] Big objects such as castle walls often
have extra resilience represented by a damage threshold. (DMG 247)
While we can make up our own ruling, I am interested whether we got any official information that can be applied here.
Is there any officially published material that describes the properties of stone, especially a wall and its resistances, immunities and damage threshold? If yes, what does it say? Bonus points if that wall was created by the spell wall of stone.