Xylobolus frustulatus

Xylobolus frustulatus, commonly known as the ceramic fungus or ceramic parchment, is an inedible species of crust fungus in the Stereaceae family. The fruit body forms small, hard, flat crust-like aggregations that resemble broken pieces of ceramic tile. These pieces are initially whitish before turning yellow-brown to gray-brown in age. The spore-bearing cells cover the upper surfaces of the fruit body. A saprobic species, it grows on well-decayed oak wood in Asia, northern Europe, and North America....read more on Wikipedia.