Jewel thief nabs massive rock

It's a day late but one man may have gone a little too far in his search for the perfect Valentine's Day gift.

Police are on the hunt for him after he ran out of a Cairns jewellery shop with a diamond worth more than $200,000 on Saturday morning.

The man, described as Caucasian with a muscular build and tanned complexion, had been discussing Argyle diamonds with a staff member before he grabbed a container carrying the expensive pink Argyle diamond and fled.

He was last seen fleeing the scene on a dark mountain bike, though whether he was off to give the valuable loot to a significant other remains unknown.