When something breaks into small pieces, especially when a rock or a building breaks into small pieces, those small pieces are called spalls.
Spalls are usually a sign of damage or decay.
Examples:
The rock spalls into tiny pieces.
The old building spalls, and pieces fall to the ground.
When I hit the wall, it spalls and makes a mess.
The cookie spalls into many crumbs when I break it.
After the earthquake, the road spalls and becomes difficult to drive on.
The ice spalls into small pieces when I drop it.
To break into small pieces, especially when talking about rocks or buildings.
When something spalls, it usually means it is getting weaker or falling apart.
Examples:
The concrete spalls after many years of use.
The old paint spalls off the wall.
When I drop the glass, it spalls into many pieces.
The metal spalls when it gets too hot.
The wood spalls after being out in the rain.
The rock spalls when it is hit with a hammer.