A spade is a tool primarily for digging, comprising a blade – typically narrower and less curved than that of a shovel – and a long handle. Early spades were made of riven wood or of animal bones (often shoulder blades). After the art of metalworking was developed, spades were made with sharper tips of metal. Before the introduction of metal spades manual labor was less efficient at moving earth, with picks being required to break up the soil in addition to a spade for moving the dirt. With a metal tip, a spade can both break and move the earth in most situations, increasing efficiency.