Snowball

Snowball quilts come from the Amish quilting tradition. The first ones date from the early 1800s.  The description is a slight misnomer, as the "round" snowball is actually an octagon.  

The pattern is created by sewing triangles onto each corner of a square block, creating the octagon.  Snowball quilts look especially stunning in two or three colors, but scrappy variations seem to be more common. Newer variations include alternating snowball blocks with Irish Chain or other blocks.