When I alighted on Kitagi, an island of just 700 people in the Seto Inland Sea, it was raining and the day was as gray as the granite the island is famous for.

I had been invited to visit the stone museum that opened in October of last year. The museum piqued my interest not because I am interested in rock mining, but because the museum is privately owned and I'd heard the owner had invested all his own resources to build it.

If you live in Tokyo, you've probably seen Kitagi stone, or even touched it, without giving a thought to where it came from, nor the long journey it made by ship from the Seto Inland Sea. Well-known buildings, bridges and torii gates have been made from Kitagi granite.