In 2008, Somalia issued the first 3-D coins to commemorate geometric shapes in mathematics: from left to right, the Pyramid, the Cube, the Orb, the Cylinder, and the Cone. The coins were made of copper nickel and silver-plated, have a denomination of $1, and bear the Coat of Arms of Somalia. The coins proved so popular with collectors that the set was re-issued in 2014. Mintage figures of both sets are unknown.
Image courtesy of StrangeBusiness.com (http://www.strangebusiness.com/content/item/168236.html)