Question

Non metal which has metallic luster.

Answer 1

-->Non metals are mostly found in nature as Solids, Liquids and gases.
--> Non metals are brittle.
---> Non metals do not posses the metallic luster because they cannot reflect light due  to the absence of free electrons in their structure.
So they appear dull except for 
⇒Iodine  and
⇒Diamond 

Answer 2

iodine and diamond are the non metallic luster