A pseudo solid is :

Pseudo solids (such as glass & pitch) lack a regular three-dimensional arrangement of atoms. 
Pitch is a viscoelastic polymer which can be natural or manufactured, derived from petroleum.
Solids are most stable in crystalline form. However, if a solid is formed rapidly (for example, when a liquid is cooled suddenly), its atoms or molecules do not have time to align themselves and may become locked in positions other than those of a regular crystal. Such resulting solids are called Pseudo solids.