$200,000 diamond stolen

A very expensive pink Argyle diamond has been stolen from a shop in Cairns.

It's believed a man was discussing the diamond with a staff member at the Lake Street store, before stealing a container with the diamond inside and fleeing just before 11 this morning.

The man was seen riding a dark mountain bike away from the store and towards the Esplanade.

He's described as being in his thirties, Caucasian, tanned, and is believed to be about 185cm tall with a muscular build.

The piece of jewellery is estimated to be worth more the $200,000.