The ancient Mesopotamians used sets of standard weights when transacting business. Regardless of size, most weights were made of stone, and were placed on balance scales opposite the object or substance being weighed. This weight was made from a type of stone known as hematite. It was carved in the shape of a sitting bear.
Hodges, Henry. Technology in the Ancient World. New York: Barnes and Noble Books, 1992.
Moss, Carol. Science in Ancient Mesopotamia. New York: Franklin Watts, 1989.
Roaf, Michael. Cultural Atlas of Mesopotamia and the Ancient Near East. New York: Facts on File, 1990.