Gem
Part of speech: noun
Definition: A precious stone, usually of substantial monetary value or prized for its beauty or shine. any precious or highly valued thing or person a gemma or leaf-bud a type of geometrid moth, Orthonama obstipata
Example sentence: SRK is a gem of a person. He told me that he is a keen viewer of 'Comedy Nights with Kapil' and his family records those episodes which he misses during shooting schedules.
Treasure
Part of speech: noun
Definition: A collection of valuable things.Any single thing one values greatly.A term of endearment.
Part of speech: verb
Definition: To consider something or someone to be precious.
Example sentence: There is more treasure in books than in all the pirate's loot on Treasure Island.