Is the gem museum in Kandy worth visiting for a history student?

The Kandy Gem Bureau and other large museums usually start with a short documentary film about the traditional mining process in Ratnapura. They often have a life size replica of a mine shaft which is quite educational. While they will certainly try to lead you to the showroom afterward, you are under no obligation to buy. The historical section provides a good overview of why the island was known as Ratnadipa or the Island of Gems.