Anyone know how much is 1 of those little diamonds worth?

Gold Rush: Alaska board is where most of the discussion for the show takes place. It was estimated that (being extremely generous) the diamonds were not worth more than ten or twenty thousand - and this was about 4 episodes away from the finale where it was revealed that they had earned a total of $5000.

The diamonds they have are of the generic, industrial use variety. They aren't worth much until you have a large quantity of them. Unless you are pulling a ton out of the ground, you won't make a profit with a crew similar to the Hoffman's in size