The largest diamond found in more than a century has been unearthed at a mine in Botswana, and the country’s president showed off the fist-sized stone to the world at a viewing ceremony Thursday.

The Botswana government says the huge 2,492-carat diamond is the second-biggest ever discovered in a mine. It’s the biggest diamond found since 1905.

The as-yet-unnamed diamond was presented to the world at the office of Botswana President Mokgweetsi Masisi. It weighs approximately half a kilogram…