Ambrosia Maple added to the bottom of a piece of Walnut. The Ambrosia was made of two glued pieces and is likely the reason for breaking.

Front view of a purchased piece of wood that exploded. There was probably a hairline fracture that caused this.

This is why it's always so important to wear a face mask. Super glue was put into a wood crack that was deeper than it looked. When it was being turned, glue started to come out and hit the mask. Super glue remover was used to try and get it off but it interacted very poorly with the material.