Spalting is the aftermath of fungus that has “attacked” wood. The marbled patterns are unique and resemble an inked sketch. Birch and beech wood can also can become spalted. Here is a piece of spalted maple found at Dueling Maples in Willow Grove, Pa. After searching through each piece of wood for spalted maple, this was one of two pieces with this being the largest at 1’ 2” x 3’ 10.”