Question

a non metal which sublimes and is non lustrous

Answer 1

Carbon dioxide oxide in solid state,  also known as dry ice is the non-lustrous non metal which sublimes at room temperature with 1 bar pressure.

Answer 2

All solids sublime.It's only that in a lion's share of them, under room temperature and weight it is insignificant.If any sort of substance has a temperature over the triple point, within the sight of a weight beneath it, it will heavenly.

According to the question,

A non metal which sublimes and is non lustrous is Iodine.