Stone or clay spindle whorls, sometimes with incised decoration, are usually the only evidence of the spinning process. They are small, pierced weights of various shapes (biconical, spherical, discoid, conical or truncated cone), which were fitted to a spindle, usually wooden, to increase the speed of the spin and twist the spun yarn. The rare spindle whorls made of semiprecious stones probably belonged to women of the ruling class or were not intended purely for practical use.